Alpha 1a adrenergic receptor antagonists

ABSTRACT

This invention relates to crystalline pharmaceutically acceptable salts of an alpha 1a adrenergic receptor antagonist, Compound A, which are useful in the treatment of benign prostatic hyperplasia. Pharmaceutical compositions employing the crystalline salts, and processes for making and using the crystalline salts and pharmaceutical compositions of Compound A are also disclosed. This invention further relates to a process for obtaining enantiomerically pure intermediate useful for the synthesis of end product alpha 1a adrenergic receptor antagonists. The end product compounds are useful for the treatment of benign prostatic hyperplasia and for relaxing lower urinary tract tissue. The invention also relates to a process for preparing a class of dihydropyrimidinone compounds of which Compound A is a member, wherein the process involves deprotonating a dihydropyrimidinone compound and then coupling the deprotonated derivative with a primary amine.

This application is a division of U.S. Ser. No. 09/122,301, filed Jul.24, 1998, now U.S. Pat. No. 6,207,444, the benefit of U.S. ProvisionalApplication Ser. No. 60/054,815, filed Aug. 5, 1997 and U.S. ProvisionalApplication Ser. No. 60/054,902, file Aug. 5, 1997.

FIELD OF THE INVENTION

The present invention provides pharmaceutically acceptable salts, andprocess for manufacture, of an alpha 1a adrenergic receptor antagonist.More specifically, the invention provides crystalline pharmaceuticallyacceptable salts (e.g., the tartrate salt) of the alpha 1a adrenergicreceptor, Compound A, having substantially improved physical propertiesas compared to the previously known amorphous salts.

The present invention also provides an improved process for making analpha 1a adrenergic receptor antagonist useful for treating benignprostatic hyperplasia. More specifically, the invention provides anenzymatic resolution of a dihydropyrimidinone methyl ester which is anintermediate in the preparation of the alpha 1a adrenergic receptorantagonist, Compound A.

The present invention further provides a chemical process for making aclass of dihydropyrimidinone compounds of which Compound A is a member.The process involves deprotonating a dihydropyrimidinone and thencoupling the deprotonated derivative with a primary amine.

BACKGROUND OF THE INVENTION

Benign prostatic hyperplasia, also known as benign prostatic hypertrophyor BPH, is an illness typically affecting men over fifty years of age,increasing in severity with increasing age. The symptoms of thecondition include, but are not limited to, increased difficulty inurination and sexual dysfunction. These symptoms are induced byenlargement, or hyperplasia, of the prostate gland. As the prostateincreases in size, it impinges on free-flow of fluids through the maleurethra. Concommitantly, the increased noradrenergic innervation of theenlarged prostate leads to an increased adrenergic tone of the bladderneck and urethra, further restricting the flow of urine through theurethra.

Recently, a number of alpha 1a adrenergic receptor antagonist compoundshave been disclosed as being useful in the treatment of BPH. These alpha1a adrenergic receptor antagonists and their utility in treating BPH andinhibiting contraction of lower urinary tract tissue are described inPCT International Application Publication No. WO 96/14846, published May23, 1996. More particularly, the compound(+)-5-Methoxycarbonyl-6-(3,4-difluorophenyl)-4-methoxymethyl-1-{N-[3-(4-(2-pyridyl)piperidin-1-yl)propyl]}-carboxamido-2-oxo-1,2,3,6-tetrahydropyrimidine,disclosed in Example 30 of WO 96/14846, and referred to herein as“Compound A,” is a potent and selective antagonist of the alpha 1aadrenergic receptor antagonist and is useful in the treatment of BPH.

Compound A is prepared according to the procedure of Example 30 in WO96/14846 or according to the processes disclosed in detail herein. Theidentification of Compound A as an alpha 1a adrenergic receptorantagonist was established according to the assays described in WO96/14846.

Preparation of an acceptable salt of Compound A suitable forpharmaceutical development proved problematic. Numerous attempts toisolate a crystalline salt form of Compound A failed as only amorphoussalts could be isolated. Additionally, the free base of Compound A wasalso isolated as an amorphous solid. The lack of a crystalline form ofCompound A necessitated that Compound A had to be isolated from reactionmixtures by chromatography on silica gel. Separation from reactionimpurities was tedious, large volumes of eluent were required, assay ofdozens of fractions for concentration and purity was required andconcentration of the desired fractions was time intensive. The productwas isolated by chromatography on gram scale as an amorphous solid.Thus, development of a kilogram scale process requiring chromatographicseparation would be expensive and time consuming, while scalability to afactory process was unknown but unlikely.

These problems were solved by identification of the crystallinepharmaceutically acceptable salts of Compound A of the presentinvention. More specifically, crystallization of pharmaceuticallyacceptable salts of Compound A directly from the crude or semi-purifiedreaction mixture obviates the need for chromatographic purification.This eliminates the tedious separation, large solvent requirements, andmultiple assay requirements. Moreover, a crystallization process allowsfor more reproducible purity and yield upon scale up. Additionally, thecrystalline tartrate salt of Compound A is isolated as a white,free-flowing solid allowing for easy isolation and manipulation. Stillanother advantage of the L-tartrate salt crystallization is that itenriches the chiral purity of Compound A.

Previous preparations of chiral Compound A were accomplished byfollowing the teaching of PCT Int. Appl. WO 96/14846, wherein theracemic dihydropyrimidinone was converted to diastereomeric ureaderivatives by treatment with 4-nitrophenyl chloroformate in thepresence of base, followed by (R)-(+)-α-methyl benzylamine. Thediastereomers were separated by chromatography on silica gel, then thechiral urea was cleaved to afford the desired (+)-dihydropyrimidinoneisomer. This teaching essentially followed the prior art set forth byAtwal, et.al. (J. Med. Chem. 1990, 33, 2629) wherein this diastereomericresolution was first described for a similar dihydropyrimidinone analog.In another report, Kappe et.al. (Tetrahedron 1992, 5473) have describedthe hydrogenolysis of a benzyl ester to afford the racemic acidderivative. The acid enantiomers were resolved by crystallization as thediastereomeric ammonium salts using either (R)-(+)-α-methyl benzylamineor (S)-(−)-α-methyl benzylamine.

The previously known methods for resolution of the dihydropyrimidinonesuffer from several problems. The approach described in the teaching ofPCT Int. Appl. WO 96/14846 or by Atwal, et. al. (J. Med. Chem. 1990, 33,2629) requires a multi-step sequence for the preparation ofdiastereomers. These must then be separated by either fractionalcrystallization or chromatography on silica gel. Finally, the purediasteromeric urea derivatives must be cleaved to their respectiveenantiomers and purified from the chiral resolving agent. In the methoddescribed by Kappe et.al. (Tetrahedron 1992, 5473) the ester substituentmust be a benzyl group in order for effective hydrogenolysis to affordthe carboxylic acid, which has been reported to be unstable. Followingresolution by fractional crystallization, the salts were cleaved withacid to afford the pure acid enantiomers. If ester derivatives weredesired, it was then necessary to esterify the carboxylic acid in anadditional step. Since none of the chemical steps described in theseprocesses are quantitative, each manipulation leads to a loss ofproduct. Separation by chromatography on silica gel requires largevolumes of solvent, multiple assays to determine purity of the collectedfractions, and time consuming concentration of the desired fractions.Conditions for the fractional crystallization of either thediastereomeric ureas or diastereomeric ammonium salts must be determinedfor each derivative. Commonly, the yield for the multi-step resolutionprocess was low.

The prior art methods depend on the efficiency of a chromatographicseparation or fractional crystallization for their success. Slightvariations in the purification conditions may easily lead to degradationof purity of the product. The multistep derivatization and separationsequence involves several chemical manipulations. The cost of obtainingthe reagents and solvents, along with the costs of disposal or recoveryof waste streams, is inefficient.

These problems of the prior art methods were solved by identification ofthe bioresolution process of the present invention. More specifically,the bioresolution process offers several advantages over these existingmethodologies. It is a one step process, run in an aqueous media, whichproceeds in high yield. This results in less wasted time and manpowerfor its practice, and requires a minimum amount of reagents, andsolvents to perform.

SUMMARY OF THE INVENTION

The present invention provides a crystalline pharmaceutically acceptablesalt of a compound A of the formula

and solvates thereof.

In one embodiment of the invention is the crystalline pharmaceuticallyacceptable salt of Compound A, and solvates thereof, wherein the salt isselected from L-tartrate, D-tartrate, citrate or benzoate salts.

In a class of the invention is the crystalline salt of Compound A of theformula

and solvates thereof.

In a subclass of the invention is the Compound A characterized by adifferential scanning calorimetry (DSC) curve selected from:

(a) a DSC curve, at a heating rate of 10° C./min in an open cup underflowing nitrogen, exhibiting a relatively broad endotherm with anextrapolated onset temperature of about 56° C., a peak temperature ofabout 90° C. and an associated heat of about 23 J/gm followed by anendotherm with an extrapolated onset temperature of about 108° C., apeak temperature of about 115° C. and an associated heat of about 13J/gm followed by an endotherm with an extrapolated onset temperature ofabout 145° C., a peak temperature of about 148° C. and an associatedheat of about 57 J/gm; or

(b) a DSC curve, at a heating rate of 10° C./min in an open cup underflowing nitrogen, exhibiting an endotherm with an extrapolated onsettemperature of about 144° C., a peak temperature of about 148° C. and anassociated heat of about 65 J/gm.

Illustrative of the invention is the Compound A characterized by anx-ray powder diffraction pattern selected from:

(a) an X-ray powder diffraction pattern characterized by d-spacings of14.91, 8.32, 6.88, 5.41, 4.74, 4.29, 4.04, 3.86, 3.75 and 3.59 Å; or

(b) an X-ray powder diffraction pattern characterized by d-spacings of13.29, 7.82, 6.63, 6.20, 5.36, 5.01, 4.59, 4.35, 4.05, 3.73 and 3.60 Å.

An illustration of the invention is a pharmaceutical compositioncomprising the crystalline salt of Compound A, or solvate thereof, and apharmaceutically acceptable carrier.

Exemplifying the invention is a pharmaceutical composition made bycombining a crystalline salt of Compound A, or solvate thereof, and apharmaceutically acceptable carrier.

Illustrating the invention is a process for making a pharmaceuticalcomposition comprising combining a crystalline salt of Compound A, orsolvate thereof, and a pharmaceutically acceptable carrier.

In another embodiment of the invention is the pharmaceutical compositionfurther comprising a therapeutically effective amount of a testosterone5-alpha reductase inhibitor. Preferably, the testosterone 5-alphareductase inhibitor is a type 1, a type 2, both a type 1 and a type 2(i.e., a three component combination comprising any of the compoundsdescribed above combined with both a type 1 testosterone 5-alphareductase inhibitor and a type 2 testosterone 5-alpha reductaseinhibitor) or a dual type 1 and type 2 testosterone 5-alpha reductaseinhibitor. More preferably, the testosterone 5-alpha reductase inhibitoris a type 2 testosterone 5-alpha reductase inhibitor. Most preferably,the testosterone 5-alpha reductase inhibitor is finasteride.

Examples of the invention are methods of treating benign prostatichyperplasia, of inhibiting contraction of prostate tissue and ofrelaxing lower urinary tract tissue in a subject in need thereof whichcomprises administering to the subject a therapeutically effectiveamount of any of the crysalline salts of Compound A, and solvatesthereof, or pharmaceutical compositions described above. In anotherembodiment of the invention are the methods of treating BPH, ofinhibiting contraction of prostate tissue and of relaxing lower urinarytract tissue in a subject in need thereof wherein the crystalline saltof Compound A, or solvate thereof, is administered in combination with atestosterone 5-alpha reductase inhibitor; preferably, the testosterone5-alpha reductase inhibitor is finasteride.

Further illustrating the invention is a process for making a crystallinepharmaceutically acceptable salt of a compound of the formula

and solvates thereof, comprising the steps of:

(a) dissolving a free base compound of the formula

 in a solvent to form a solution; and

(b) treating the solution from step (a) with an acid to form thecrystalline pharmaceutically acceptable salt. The term “treating,” asused herein, includes both the process where the acid is added to thesolution from step (a), as well as the process where the solution fromstep (a) is added to the acid.

An illustration of the invention is the process wherein the acid is asolution of the acid in a second solvent (which can be the same ordifferent from the first solvent used to dissolve the free base ofCompound A).

Further exemplifying the invention is the process wherein the acid isselected from L-tartaric acid, D-tartaric acid, citric acid or benzoicacid. Preferably, the acid is L-tartaric acid.

More particularly illustrating the invention is the process wherein the(first) solvent for dissolving Compound A free base and the (second)solvent for dissolving the acid are each independently selected frommethanol, ethanol, 2-propanol, ethyl acetate, isopropyl acetate,butanol, hexanes, toluene or a mixture thereof. Preferably, the firstand second solvents for dissolving Compound A free base and the acid,respectively, are each independently selected from ethanol, 2-propanol,or a mixture thereof.

More specifically exemplifying the invention is the process for making acrystalline pharmaceutically acceptable salt of a compound of theformula

and solvates thereof, comprising the steps of:

(a) dissolving a free base compound of the formula

 in a solvent selected from ethanol, 2-propanol, or a mixture thereof,to form a solution; and

(b) treating the solution from step (a) with L-tartaric acid to form thecrystalline pharmaceutically acceptable salt of the formula

and solvates thereof.

More specifically illustrating the invention is a process for making acrystalline pharmaceutically acceptable salt of a compound of theformula

and solvates thereof, comprising the steps of:

(a) dissolving a free base compound of the formula

 in a first solvent selected from methanol, ethanol, 2-propanol, ethylacetate, isopropyl acetate, butanol, hexanes, toluene or a mixturethereof, to form a solution; and

(b) treating the solution from step (a) with a solution of L-tartaricacid in a second solvent selected from methanol, ethanol, 2-propanol,ethyl acetate, isopropyl acetate, butanol, hexanes, toluene or a mixturethereof, to form the crystalline pharmaceutically acceptable salt of theformula

and solvates thereof.

An additional illustration of the invention is a crystallinepharmaceutically acceptable salt, and solvates thereof, made by any ofthe processes described above.

Still further exemplifying the invention is a crystallinepharmaceutically acceptable salt, and solvates thereof, made bydissolving a free base compound of the formula

in a solvent to form a solution; and treating the solution with an acidselected from L-tartaric acid, D-tartaric acid, citric acid or benzoicacid to form the crystalline pharmaceutically acceptable salt.Preferably, the acid is L-tartaric acid.

An additional example of the invention is the use of any of thecrystalline pharmaceutically acceptable salts of Compound A, andsolvates thereof, described above in the preparation of a medicamentfor: a) the treatment of benign prostatic hyperplasia; b) relaxing lowerurinary tract tissue; or c) inhibiting contraction of prostate tissue;in a subject in need thereof.

Another illustration of the invention is the use of any of thecrystalline pharmaceutically acceptable salts of Compound A, andsolvates thereof, described above and a 5-alpha reductase inhibitor forthe manufacture of a medicament for: a) treating benign prostatichyperplasia; b) relaxing urethral smooth muscle; or c) inhibitingcontraction of prostate tissue which comprises an effective amount ofthe alpha 1a antagonist compound and an effective amount of 5-alphareductase inhibitor, together or separately. Preferably, the 5-alphareductase inhibitor is finasteride.

In another aspect of the invention is a crystalline salt of the compoundof the formula

Preferably, the salt is selected from a L-tartrate, D-tartrate, citrate,benzoate salt, acetate, hydrochloride, sulfate, methane sulfonate orp-toluene sulfonate of (6). Most preferably, the crystalline compound ofthe formula

The present invention also provides a process to afford a compound ofthe formula IA

comprising the steps of

(a) contacting a racemic compound of the formula

 with a protease enzyme to form a mixture; and

(b) aging the mixture from step (a) to afford the compound IA.

In one embodiment of the invention is the process wherein the compoundIA which is obtained is substantially free of its (R)-enantiomer. Theterm “substantially free of its R- enantiomer” means that the desired S-enantiomer is obtained in greater than about 75% ee (enantiomericexcess), preferably, greater than about 90% ee, and most preferably,greater than about 98% ee. Preferably, the compound IA is produced ingreater than 75% ee. More preferably, the compound IA is produced ingreater than 90% ee. Most preferably, the compound IA is produced ingreater than 98% ee.

In a class of the invention is the process wherein the protease enzymeis selected from Proteinase K or a fungal enzyme produced by a closelyrelated organism to Tritirachium album (the strain used to produceProteinase K) or Subtilisin or a protease enzyme preparation obtainedfrom Metarhizium anisopliae MF 6527. Preferably, the protease enzyme isSubtilisin.

In a subclass of the invention is the process further comprising thestep of isolating the compound of formula I.

Illustrative of the invention is the process further comprising reactingthe compound of formula IA.

with 3-[4-(2-pyridyl)piperidin-1-yl]propylamine to form Compound A

Illustrating the invention is the process wherein the reaction is agedfor a period between about 1 day and about 3 weeks. Preferably, thereaction is aged for a period between about 5 and about 18 days.

Exemplifying the invention is the process wherein the reaction is agedat a pH between about 6 and about 9, preferably about 8.5.

An illustration of the invention is the process wherein the reaction isaged at a temperature between about 15° C. and about 50° C. Preferably,the reaction is aged at a temperature between about 30° C. to about 40°C. Most preferably, the reaction is aged at a temperature of about 37°C.

An example of the invention is a process to afford a compound of theformula IA

comprising the steps of

(a) contacting a racemic compound of the formula

 with water to form an aqueous mixture;

(b) contacting the aqueous mixture from step (a) with a polysaccharidegum to form an emulsion;

(c) contacting the emulsion from step (b) with a solvent selected fromDMSO, iso-octane, isopropanol, methanol, hexane or acetonitrile to forma solvent mixture;

(d) contacting the solvent mixture from step (c) with a protease enzyme,preferably, a protease enzyme selected from Proteinase K or Subtilisin,to form a reaction mixture; and

(e) aging the reaction mixture from step (d) at a temperature betweenabout 15° C. and about 50° C. for a period between about 1 day and about3 weeks to afford the compound IA.

Further illustrating the invention is the process wherein the compoundIA which is obtained is substantially free of its (R)-enantiomer.Preferably, the compound IA is produced in greater than 75% ee. Morepreferably, the compound IA is produced in greater than 90% ee. Mostpreferably, the compound IA is produced in greater than 98% ee.

Further exemplifying the invention is the process wherein thepolysaccharide is selected from guar gum, arabic gum, or xanthan gum.Preferably, the polysaccharide is xanthan gum.

More particularly illustrating the invention is the process wherein thesolvent is acetonitrile.

Another illustration of the invention is the process wherein the aqueousmixture from step (a) is buffered to a pH between about 6 and about 9,preferably about 8.5.

More specifically exemplifying the invention is the process wherein thereaction is aged for a period between about 5 and about 18 days.

An additional example of the invention is the process wherein thereaction is aged at a temperature between about 30° C. to about 40° C.,preferably, about 37° C.

More specifically illustrating the invention is the process furthercomprising isolating the compound of formula IA.

More particularly exemplifying the invention is the process furthercomprising reacting the compound of formula IA

with 3-[4-(2-pyridyl)piperidin-1-yl]propylamine to form Compound A.

In another aspect of the invention is a compound of the formula IA

and salts thereof.

A further aspect of this invention is a chemical process for making aclass of compounds of which Compound A is a member. This class ofcompounds can be represented by Formula (I):

and it is prepared by treating a dihydropyrimidinone compound of Formula(II):

(the preparation of which is described in International ApplicationWO97/21687, published Jun. 19, 1997) with a deprotonation agent, andcontacting the deprotonated compound of Formula (II) with carbonyldiimidazole (“CDI”), followed by coupling the product of that reactionwith an amine of Formula (III):

H₂N—R  (III)

Definitions for the groups R and R1 to R7 in the formulae are providedbelow.

The process of the invention offers significant advantages over theconventional procedure for coupling a primary amine and adihydropyrimidinone. The conventional procedure involves the coupling ofthe amine with a 4-nitrophenylchloroformate derivative of thedihydropyrimidinone, which is itself prepared by deprotonating thedihydropyrimidinone with, for example, lithium diisopropylamide and thenreacting the deprotonated compound with 4-nitrophenylchloroformate. Whenboth the N1 and N3 positions on the dihydropyrimidinone areunsubstituted (i.e., hydrogen atoms are attached to the ring nitrogens),the conventional procedure typically provides poor selectivity betweenthe N1 and N3 positions and often gives undesired bis-acylation. Inaddition, a large excess of base and 4-nitrophenylchloroformate (e.g.,from about 3 to about 4 equivalents) is required to achieve goodconversions. In sharp contrast, the process of the invention requiresonly a slight excess of CDI to achieve high conversions (e.g., greaterthan about 85% coupling), and, for dihydropyrimidinones havingunsubstituted nitrogens, coupling occurs predominantly or exclusively atthe N3 position, eliminating the need to protect and deprotect the N1position to avoid the formation of bis-coupled products.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides crystalline pharmaceutically acceptablesalts of the potent and selective alpha 1a adrenergic receptorantagonist, Compound A, pharmaceutical compositions containing them, andmethods of making and using the crystalline pharmaceutically acceptablesalts of Compound A. The crystalline pharmaceutically acceptable saltsof Compound A and pharmaceutical compositions of the present inventionare useful in eliciting an alpha 1a antagonizing effect, in theprevention and/or treatment of BPH, and in relaxing lower urinary tracttissue.

For use in medicine, the salts of the compounds of this invention referto non-toxic “pharmaceutically acceptable salts.” Other salts may,however, be useful in the preparation of the compounds according to theinvention or of their pharmaceutically acceptable salts. Suitablepharmaceutically acceptable salts of the compounds of this inventioninclude acid addition salts which may, for example, be formed by mixinga solution of the compound according to the invention with a solution ofa pharmaceutically acceptable acid such as hydrochloric acid, sulphuricacid, fumaric acid, maleic acid, succinic acid, acetic acid, benzoicacid, citric acid, tartaric acid, carbonic acid or phosphoric acid.

The crystalline pharmaceutically acceptable salts of Compound A andpharmaceutical compositions of the present invention exhibit highselectivity for the human alpha 1a adrenergic receptor. One implicationof this selectivity is that these compounds display selectivity forlowering intraurethral pressure without substantially affectingdiastolic blood pressure.

The term “Compound A,” as used herein refers to the free base shownbelow:

Compound A and its utility for antagonizing the alpha 1a adrenergicreceptor, for treating BPH and for inhibiting lower urinary tract tissueis described in detail in WO 96/14846. Compound A is readily preparedaccording to the procedure of Example 30 in WO 96/14846, or according tothe processes disclosed herein.

The term “selective alpha 1a adrenergic receptor antagonist,” as usedherein, refers to an alpha 1a antagonist compound which is at least tenfold selective for the human alpha 1a adrenergic receptor as compared tothe human alpha 1b, alpha 1d, alpha 2a, alpha 2b and alpha 2c adrenergicreceptors.

The term “lower urinary tract tissue,” as used herein, refers to andincludes, but is not limited to, prostatic smooth muscle, the prostaticcapsule, the urethra and the bladder neck.

The term “subject,” as used herein refers to an animal, preferably amammal, most preferably a human, who has been the object of treatment,observation or experiment.

The term “therapeutically effective amount” as used herein means thatamount of active compound or pharmaceutical agent that elicits thebiological or medicinal response in a tissue, system, animal or humanthat is being sought by a researcher, veterinarian, medical doctor orother clinician, which includes alleviation of the symptoms of thedisease being treated.

The present invention also provides pharmaceutical compositionscomprising the crystalline pharmaceutically acceptable salts of CompoundA, and solvates thereof, in association with a pharmaceuticallyacceptable carrier. Preferably these compositions are in unit dosageforms such as tablets, pills, capsules, powders, granules, sterileparenteral solutions or suspensions, metered aerosol or liquid sprays,drops, ampoules, auto-injector devices or suppositories; for oral,parenteral, intranasal, sublingual or rectal administration, or foradministration by inhalation or insufflation. Alternatively, thecompositions may be presented in a form suitable for once-weekly oronce-monthly administration; for example, an insoluble salt of theactive compound, such as the decanoate salt, may be adapted to provide adepot preparation for intramuscular injection. For preparing solidcompositions such as tablets, the principal active ingredient is mixedwith a pharmaceutical carrier, e.g. conventional tableting ingredientssuch as corn starch, lactose, sucrose, sorbitol, talc, stearic acid,magnesium stearate, dicalcium phosphate or gums, and otherpharmaceutical diluents, e.g. water, to form a solid preformulationcomposition containing a homogeneous mixture of a compound of thepresent invention, or a pharmaceutically acceptable salt thereof. Whenreferring to these preformulation compositions as homogeneous, it ismeant that the active ingredient is dispersed evenly throughout thecomposition so that the composition may be readily subdivided intoequally effective unit dosage forms such as tablets, pills and capsules.This solid preformulation composition is then subdivided into unitdosage forms of the type described above containing from 0.1 to about500 mg of the active ingredient of the present invention. The tablets orpills of the novel composition can be coated or otherwise compounded toprovide a dosage form affording the advantage of prolonged action. Forexample, the tablet or pill can comprise an inner dosage and an outerdosage component, the latter being in the form of an envelope over theformer. The two components can be separated by an enteric layer whichserves to resist disintegration in the stomach and permits the innercomponent to pass intact into the duodenum or to be delayed in release.A variety of materials can be used for such enteric layers or coatings,such materials including a number of polymeric acids and mixtures ofpolymeric acids with such materials as shellac, cetyl alcohol andcellulose acetate.

As used herein, the term “composition” is intended to encompass aproduct comprising the specified ingredients in the specified amounts,as well as any product which results, directly or indirectly, fromcombination of the specified ingredients in the specified amounts.

The liquid forms in which the novel compositions of the presentinvention may be incorporated for administration orally or by injectioninclude aqueous solutions, suitably flavoured syrups, aqueous or oilsuspensions, and flavoured emulsions with edible oils such as cottonseedoil, sesame oil, coconut oil or peanut oil, as well as elixirs andsimilar pharmaceutical vehicles. Suitable dispersing or suspendingagents for aqueous suspensions include synthetic and natural gums suchas tragacanth, acacia, alginate, dextran, sodium carboxymethylcellulose,methylcellulose, polyvinyl-pyrrolidone or gelatin.

The present invention includes within its scope prodrugs of thecompounds of this invention. In general, such prodrugs will befunctional derivatives of the compounds of this invention which arereadily convertible in vivo into the required compound. Thus, in themethods of treatment of the present invention, the term “administering”shall encompass the treatment of the various conditions described withthe compound specifically disclosed or with a compound which may not bespecifically disclosed, but which converts to the specified compound invivo after administration to the patient. Conventional procedures forthe selection and preparation of suitable prodrug derivatives aredescribed, for example, in “Design of Prodrugs,” ed. H. Bundgaard,Elsevier, 1985. Metabolites of these compounds include active speciesproduced upon introduction of compounds of this invention into thebiological milieu.

The invention involves the formation of crystalline pharmaceuticallyacceptable salts of the alpha 1a adrenergic receptor antagonist,Compound A, by treatment of the free base dissolved in a solvent with anacid. More specifically, the free base of Compound A is dissolved in asolvent and treated with about 0.5 to about 2.0 equivalents of the acidat a temperature of about 20 to about 80° C. to provide the crystallinesalt of Compound A. Preferably, the free base of Compound A is dissolvedin a solvent and treated with about 0.9 to about 1.3 equivalents of theacid at a temperature of about 35 to about 65° C. to provide thecrystalline salt of Compound A. In a preferred embodiment, the free baseof Compound A is dissolved in a solvent and treated with about 1.0 toabout 1.1 equivalents of the acid at a temperature of about 45 to about55° C. to provide the crystalline salt of Compound A. The acid ispreferably selected from L-tartaric acid, D-tartaric acid, citric acidor benzoic acid. If desired, the acid can be added as a solution in asolvent which can be the same or different from the solvent used todissolve the Compound A free base. In a particularly preferedembodiment, about 1.0 equivalent of L-tartaric acid is added to thesolution of Compound A free base in the solvent at a temperature ofabout 50±10° C.

In the processes of making the crystalline pharmaceutically acceptablesalts of the instant invention, the term “treating” or “treatment” whichrefers to the treatment of (or treating) Compound A in a solvent (i.e.,“Compound A solution”) with an acid, as used herein, includes both theaddition of the acid to the Compound A solution, as well as the additionof the Compound A solution to the acid. That is, the order of additionis not important to the success of the process for forming thecrystalline pharmaceutically acceptable salts of Compound A. In apreferred process, the acid is added to a solution of Compound A in asolvent.

A wide variety of solvents can be utilized as long as the Compound Afree base is soluble in the solvent. Similarly, when the acid is addedas a solution of the acid in a solvent, a wide variety of solvents canbe used. Thus, suitable solvents for dissolving Compound A free baseand/or the acid include, but are not limited to, water or esters,ketones, amides, ethers, alcohols and hydrocarbons, or mixtures thereof.Preferably, esters (e.g., ethyl acetate, isopropyl acetate), alcohols(e.g., methanol, ethanol, 2-propanol, butanol), hydrocarbons (e.g.,hexanes, toluene) or mixtures thereof, are used as the solvent; morepreferably, alcohols; most preferably, ethanol, or 2-propanol, ormixtures thereof, is utilized as the solvent. In a particularlypreferred embodiment, 2-propanol is used as the solvent to provide thecrystalline L-tartrate salt of Compound A.

Thus, one aspect of the invention involves the formation of acrystalline pharmaceutically acceptable salt of the alpha 1a adrenergicreceptor antagonist, Compound A, by treatment of the free base inethanol or 2-propanol at a temperature about 50±10° C. (preferably,about 50° C.), with L-tartaric acid in ethanol solution followed bycrystallization. The resulting L-tartrate salt is isolated as acrystalline white, free-flowing solid. The L-tartrate salt has desirablepharmaceutical properties, such as bioavailability, tolerability,stability, low hygroscopicity and pH. In addition, the L-tartrate saltaffords purification, enrichment of chiral purity and ease of handlingof Compound A.

In general, the compounds of the present invention comprise Compound Aas a crystalline pharmaceutically acceptable salt. In a preferredembodiment, the compound comprises a crystalline pharmaceuticallyacceptable salt of Compound A selected from the L-tartrate, D-tartrate,citrate or benzoate salts. In a particularly preferred embodiment, thecompound comprises the crystalline L-tartrate salt of Compound A.

The compounds and pharmaceutical compositions of the present inventionare useful in eliciting an alpha 1a antagonizing effect. Thus, thecompounds and pharmaceutical compositions of this invention are usefulin the prevention and/or treatment of BPH and for relaxing lower urinarytract tissue.

For these purposes, the compounds of the present invention may beadministered orally, parenterally (including subcutaneous injections,intravenous, intramuscular, intrasternal injection or infusiontechniques), by inhalation spray, or rectally, in dosage unitformulations containing conventional non-toxicpharmaceutically-acceptable carriers, adjuvants and vehicles.

Thus, in accordance with the present invention there is further provideda method of treating and a pharmaceutical composition for treating BPHand for relaxing lower urinary tract tissue. The treatment involvesadministering to a patient in need of such treatment a crystallinepharmaceutically acceptable salt of Compound A, or a solvate thereof; ora pharmaceutical composition comprising a pharmaceutical carrier and atherapeutically effective amount of a crystalline pharmaceuticallyacceptable salt of Compound A of the present invention, or a solvatethereof.

These pharmaceutical compositions may be in the form oforally-administrable suspensions or tablets; nasal sprays; sterileinjectable preparations, for example, as sterile injectable aqueous oroleagenous suspensions or suppositories.

When administered orally as a suspension, these compositions areprepared according to techniques well-known in the art of pharmaceuticalformulation and may contain microcrystalline cellulose for impartingbulk, alginic acid or sodium alginate as a suspending agent,methylcellulose as a viscosity enhancer, and sweeteners/flavoring agentsknown in the art. As immediate release tablets, these compositions maycontain microcrystalline cellulose, dicalcium phosphate, starch,magnesium stearate and lactose and/or other excipients, binders,extenders, disintegrants, diluents and lubricants known in the art.

When administered by nasal aerosol or inhalation, these compositions areprepared according to techniques well-known in the art of pharmaceuticalformulation and may be prepared as solutions in saline, employing benzylalcohol or other suitable preservatives, absorption promoters to enhancebioavailability, fluorocarbons, and/or other solubilizing or dispersingagents known in the art.

The injectable solutions or suspensions may be formulated according toknown art, using suitable non-toxic, parenterally-acceptable diluents orsolvents, such as mannitol, 1,3-butanediol, water, Ringer's solution orisotonic sodium chloride solution, or suitable dispersing or wetting andsuspending agents, such as sterile, bland, fixed oils, includingsynthetic mono- or diglycerides, and fatty acids, including oleic acid.

When rectally administered in the form of suppositories, thesecompositions may be prepared by mixing the drug with a suitablenon-irritating excipient, such as cocoa butter, synthetic glycerideesters or polyethylene glycols, which are solid at ordinarytemperatures, but liquidify and/or dissolve in the rectal cavity torelease the drug.

Compounds of this invention may be administered in any of the foregoingcompositions and according to dosage regimens established in the artwhenever specific blockade of the human alpha 1a adrenergic receptor isrequired.

The daily dosage of the products may be varied over a wide range from0.01 to 1,000 mg per adult human per day. For oral administration, thecompositions are preferably provided in the form of tablets containing0.01, 0.05, 0.1, 0.5, 1.0, 2.5, 5.0, 10.0, 15.0, 25.0, 50.0, 100, 250and 500 milligrams of the active ingredient for the symptomaticadjustment of the dosage to the patient to be treated. A medicamenttypically contains from about 0.01 mg to about 500 mg of the activeingredient, preferably, from about 1 mg to about 100 mg of activeingredient. An effective amount of the drug is ordinarily supplied at adosage level of from about 0.0002 mg/kg to about 20 mg/kg of body weightper day. Preferably, the range is from about 0.001 to 10 mg/kg of bodyweight per day, and especially from about 0.001 mg/kg to 7 mg/kg of bodyweight per day. The compounds may be administered on a regimen of 1 to 4times per day. It will be understood, however, that the specific doselevel and frequency of dosage for any particular patient may be variedand will depend upon a variety of factors including the activity of thespecific compound employed, the metabolic stability and length of actionof that compound, the age, body weight, general health, sex, diet, modeand time of administration, rate of excretion, drug combination, theseverity of the particular condition, and the host undergoing therapy.

Compounds of this patent disclosure may be used alone at appropriatedosages defined by routine testing in order to obtain optimal antagonismof the human alpha 1a adrenergic receptor while minimizing any potentialtoxicity. In addition, co-administration or sequential administration ofother agents which alleviate the effects of BPH is desirable. Thus, inone embodiment, this includes administration of compounds of thisinvention and a human testosterone 5-α reductase inhibitor. Includedwith this embodiment are inhibitors of 5-alpha reductase iso enzyme 2.Many such compounds are now well known in the art and include suchcompounds as PROSCAR®, (also known as finasteride, a 4-Aza-steroid; seeU.S. Pat. Nos. 4,377,584 and 4,760,071, for example). In addition toPROSCAR®, which is principally active in prostatic tissue due to itsselectivity for human 5-α reductase isozyme 2, combinations of compoundswhich are specifically active in inhibiting testosterone 5-alphareductase isozyme 1 and compounds which act as dual inhibitors of bothisozymes 1 and 2, are useful in combination with compounds of thisinvention. Compounds that are active as 5α-reductase inhibitors havebeen described in WO93/23420, EP 0572166; WO 93/23050; WO93/23038;WO93/23048; WO93/23041; WO93/23040; WO93/23039; WO93/23376; WO93/23419,EP 0572165; WO93/23051.

The dosages of the alpha 1a adrenergic receptor and testosterone 5-alphareductase inhibitors are adjusted when combined to achieve desiredeffects. As those skilled in the art will appreciate, dosages of the5-alpha reductase inhibitor and the alpha 1a adrenergic receptorantagonist may be independently optimized and combined to achieve asynergistic result wherein the pathology is reduced more than it wouldbe if either agent were used alone. In accordance with the method of thepresent invention, the individual components of the combination can beadministered separately at different times during the course of therapyor concurrently in divided or single combination forms. The instantinvention is therefore to be understood as embracing all such regimes ofsimultaneous or alternating treatment and the term “administering” is tobe interpreted accordingly.

Thus, in one preferred embodiment of the present invention, a method oftreating BPH is provided which comprises administering to a subject inneed of treatment any of the compounds of the present invention incombination with finasteride effective to treat BPH. The dosage offinasteride administered to the subject is about 0.01 mg per subject perday to about 50 mg per subject per day in combination with an alpha 1aantagonist. Preferably, the dosage of finasteride in the combination isabout 0.2 mg per subject per day to about 10 mg per subject per day,more preferably, about 1 to about 7 mg per subject to day, mostpreferably, about 5 mg per subject per day.

For the treatment of benign prostatic hyperplasia, compounds of thisinvention exhibiting alpha 1a adrenergic receptor blockade can becombined with a therapeutically effective amount of a 5α-reductase 2inhibitor, such as finasteride, in addition to a 5α-reductase 1inhibitor, such as 4,7β-dimethyl-4-aza-5α-cholestan-3-one, in a singleoral, systemic, or parenteral pharmaceutical dosage formulation.Alternatively, a combined therapy can be employed wherein the alpha 1aadrenergic receptor antagonist and the 5α-reductase 1 or 2 inhibitor areadministered in separate oral, systemic, or parenteral dosageformulations. See, e.g., U.S. Pat. Nos. 4,377,584 and 4,760,071 whichdescribe dosages and formulations for 5α-reductase inhibitors.

Abbreviations used in the instant specification, particularly theSchemes and Examples, are as follows:

Aq=aqueous

Ac=acetyl

CDI=carbonyl diimidazole

DMF=N,N-dimethylformamide

DMSO=dimethylsulfoxide

EtOH=ethanol

IPAc=isopropyl acetate

LDA=lithium diisopropylamide

Me=methyl

MeOH=methanol

MTBE=methyl tert-butyl ether

t-Bu=tertiary-butyl or tert-butyl

THF=tetrahydrofuran

Additional abbreviations used in the instant specification, particularlyin the Schemes, are as follows:

AcOH=acetic acid

BINAP=2,2′-Bis(diphenylphosphino)-1,1′-binaphthyl

Boc or BOC=t-butyloxycarbonyl

BOC₂O=di-tert-butyl dicarbonate

BuOH=butanol

n-BuLi=n-butyllithium

Cbz-Cl=benzyloxycarbonyl chloride

DPPA=diphenylphosphoryl azide

Et₃N=triethylamine

EtOAc=ethyl acetate

HPLC=high performance liquid chromatography

PCTLC (or PCC)=preparative centrifugal thin layer chromatography

Ph=phenyl

pTOS=p-toluenesulfonic acid

Tos₂O or TOS₂O=p-toluenesulfonic anhydride

Compound A L-tartrate salt, i.e.,(+)-5-Methoxycarbonyl-6-(3,4-difluorophenyl)-4-methoxy-carbonyl-1-{N-[3-(4-(2-pyridyl)piperidin-1-yl)propyl]}-carboxamido-1,2,3,6-tetrahydro-2-oxopyrimidineL-tartrate salt, (1) may be prepared according to Scheme 1. Racemic 2 isreadily prepared from commercially available 3,4-difluorobenzaldehyde,methyl 4-methoxyacetoacetate, and urea following the teaching of PCTInternational Application Publication No. WO97/21687, published Jun. 19,1997. Enantiomeric resolution to afford (+)-2 may be accomplished byconventional techniques known to those skilled in the art, or byremoving (−)-2 via ester hydrolysis with commercially available proteaseenzyme, for example Subtilisin. (+)-2 is coupled with3-[4-(2-pyridyl)piperidin-1-yl]propylamine, (6) (Scheme 2), utilizingcarbonyl diimidazole, to afford(+)-5-methoxycarbonyl-6-(3,4-difluorophenyl)-4-methoxycarbonyl-1-{N-[3-(4-(2-pyridyl)piperidin-1-yl)propyl]}carboxamido-1,2,3,6-tetrahydro-2-oxopyrimidine, (3). Crystallization ofthe(+)-5-methoxycarbonyl-6-(3,4-difluorophenyl)-4-methoxycarbonyl-1-{N-[3-(4-(2-pyridyl)piperidin-1-yl)propyl]}carboxamido-1,2,3,6-tetrahydro-2-oxopyrimidineL-tartrate salt, (1) is accomplished by treating a solution of 3 withL-tartaric acid.

3-[4-(2-pyridyl)piperidin-1-yl]propylamine, (6) can be preparedfollowing the teachings of WO 96/14846, or by the procedure outlined inScheme 2 wherein commercially available 2,4′-dipyridyl is alkylated with3-bromopropylamine hydrobromide to afford pyridinium salt 4. Reductionof 4 with sodium borohydride affords 5 which is hydrogenated overPearlman's catalyst to afford3-[4-(2-pyridyl)piperidin-1-yl]propylamine, (6). If desired, 6 may beused directly in the preparation of 3, or it may be crystallized as itsL-tartrate salt 7.

Thus, in another aspect of the invention is a crystalline salt of theside chain intermediate 3-[4-(2-pyridyl)piperidin-1-yl]propylamine, (6).The crystalline salts of intermediate 6 are prepared by treatment of thefree base 6 dissolved in a solvent with an acid. More specifically, thefree base is dissolved in a solvent and treated with about 0.5 to about2 equivalents of an acid, which can be chosen from a mineral acid (suchas HCl or H₂SO₄), a sulfonic acid (such as methane sulfonic acid orp-toluene sulfonic acid) or an organic acid (such as acetic acid,benzoic acid, citric acid, D- or L-tartaric acid) at a temperature ofabout 20 to about 100° C., preferably, about 50-80° C., most preferably,about 60-70° C., to provide the crystalline salt of 6. In a preferredembodiment of this aspect of the invention, the free base 6 is dissolvedin a solvent and treated with about 0.8 to 1.5 equivalents of an organicacid, most preferably, about 1.0 to 1.1 equivalents of L-tartaric acid,to form the crystalline salt of 6. If desired, the acid can be added asa solution in a solvent which can be the same or different from thesolvent used to dissolve the compound 6 free base. Additionally, theterm “treating” or “treatment” which refers to the treatment of (ortreating) the free base of 6 in a solvent with an acid, as used herein,includes both the addition of the acid to the solution of 6 in thesolvent, as well as the addition of the Compound A solution to the acid.That is, the order of addition is not important to the success of theprocess for forming the crystalline salts of 6.

A wide variety of solvents can be utilized as long as intermediate 6free base is soluble in the solvent. Similarly, when the acid is addedas a solution of the acid in a solvent, a wide variety of solvents canbe used. Thus, any common organic solvent such as, but not limited to,ethers, hydrocarbons, amides, alcohols, esters, ketones, or mixturesthereof. Preferably, esters (e.g., ethyl acetate, isopropyl acetate),alcohols (e.g., methanol, ethanol, 2-propanol, butanol), hydrocarbons(e.g., hexanes, toluene) or mixtures thereof, are used as the solvent;more preferably, alcohols; most preferably, ethanol is utilized as thesolvent for dissolving intermediate 6 prior to treatment with the acid.

Crystallization of the side chain 6 as a salt affords severaladvantages. It allows for the removal of process impurities from theside chain in a convenient purification step without the need for achromatographic purification. Typical silica gel chromatography is aninefficient process for purification in that it requires large amountsof eluent, assay of multiple fractions to determine purity, and timeconsuming concentration of the rich fractions to afford the product as athick oil. This oil is difficult to assay, weigh, transfer, and handleas needed for subsequent steps. The crystalline salt is readily preparedfrom the crude side chain, it removes process impurities efficiently,and it is an easily isolated and handled material. These properties makeits subsequent use more efficient.

The present invention also provides an improved process for making analpha 1a adrenergic receptor antagonist useful for treating benignprostatic hyperplasia. More specifically, the invention provides anenzymatic resolution of a dihydropyrimidinone methyl ester which is anintermediate in the preparation of the alpha 1a adrenergic receptor,Compound A. Compound A and pharmaceutical compositions thereof areuseful in eliciting an alpha 1a antagonizing effect, in the preventionand/or treatment of BPH, and in relaxing lower urinary tract tissue.

Compound A, and pharmaceutically acceptable salts thereof exhibit highselectivity for the human alpha 1a adrenergic receptor. One implicationof this selectivity is that these compounds display selectivity forlowering intraurethral pressure without substantially affectingdiastolic blood pressure.

The end product compounds (e.g., Compound A) synthesized from theintermediates of the present invention are useful in eliciting an alpha1a antagonizing effect. Thus, the compounds and pharmaceuticalcompositions of this invention are useful in the prevention and/ortreatment of BPH and for relaxing lower urinary tract tissue.

For these purposes, the end product compounds of the present inventionmay be administered orally, parenterally (including subcutaneousinjections, intravenous, intramuscular, intrasternal injection orinfusion techniques), by inhalation spray, or rectally, in dosage unitformulations containing conventional non-toxicpharmaceutically-acceptable carriers, adjuvants and vehicles.

The daily dosage of the end product compounds made by the process of thepresent invention may be varied over a wide range from 0.01 to 1,000 mgper adult human per day. For oral administration, the compositions arepreferably provided in the form of tablets containing 0.01, 0.05, 0.1,0.5, 1.0, 2.5, 5.0, 10.0, 15.0, 25.0, 50.0, 100, 250 and 500 milligramsof the active ingredient for the symptomatic adjustment of the dosage tothe patient to be treated. A medicament typically contains from about0.01 mg to about 500 mg of the active ingredient, preferably, from about1 mg to about 100 mg of active ingredient. An effective amount of thedrug is ordinarily supplied at a dosage level of from about 0.0002 mg/kgto about 20 mg/kg of body weight per day. Preferably, the range is fromabout 0.001 to 10 mg/kg of body weight per day, and especially fromabout 0.001 mg/kg to 7 mg/kg of body weight per day. The compounds maybe administered on a regimen of 1 to 4 times per day. It will beunderstood, however, that the specific dose level and frequency ofdosage for any particular patient may be varied and will depend upon avariety of factors including the activity of the specific compoundemployed, the metabolic stability and length of action of that compound,the age, body weight, general health, sex, diet, mode and time ofadministration, rate of excretion, drug combination, the severity of theparticular condition, and the host undergoing therapy.

The processes and intermediates of this invention are useful for thepreparation of end-product compounds such as Compound A that are usefulfor antagonizing the alpha 1a adrenergic receptor, the prevention ortreatment of BPH, for inhibiting contraction of prostate tissue and forrelaxing lower urinary tract tissue.

The term “contacting,” as used herein, refers to the step of combiningtwo or more reactants (i.e., contacting two or more reactants with eachother) where the order of addition of the reactants is not important.Thus, for example, in the step of “contacting a racemic compound (±)-2with water,” the term “contacting” means that the (+)-2 can be added towater, or that the water can be added to (±)-2.

The term “aging,” as used herein, refers to the step of allowing thereactants (e.g., protease enzyme and racemate (±)-2) to stay in contactwith each other.

The invention involves a process for producing(+)-(S)-dihydropyrimidinone (DHP) methyl ester, i.e., (+)-2, from theracemate by resolution using proteases as shown in Scheme 3.

In general, an amount of racemic ester (±)-2 is added to water which mayor may not be buffered at a pH between about 6 and about 9, preferablyabout 8.5. The aqueous ester (±)-2 mixture may optionally be blendedwith 10 g/l or less of a polysaccharide gum to form an emulsion. Anypolysaccharide gum known to one of ordinary skill in the art may beused; preferably, the gum is selected from guar gum, arabic gum, orxanthan gum; most preferably, xanthan gum. A water-miscible orwater-immiscible organic solvent, such as DMSO, iso-octane, isopropanol,methanol, hexane, or preferably, acetonitrile, may optionally be addedat a concentration of about 20% or less, preferably a concentration ofabout 9%. A protease enzyme, such as Proteinase K or a fungal enzymeproduced by a closely related organism to Tritirachium album (the strainused to produce Proteinase K) or Subtilisin or a protease enzymepreparation obtained from Metarhizium anisopliae MF 6527, is added. Theresulting reaction is stirred and allowed to age at a temperaturebetween about 15° C. and about 50° C., preferably about 30° C. to about40° C., most preferably about 37° C., for a period of time of betweenabout 1 day and about 3 weeks, preferably, between about 5 and about 18days, or until a desired degree of resolution has been achieved.

Metarhizium anisopliae, MF6527, is in the culture collection of Merck &Co., Inc., Rahway, N.J. A sample of the Metarhizium anisopliae MF6527was deposited under the Budapest Treaty at the American Type CultureCollection (ATCC), 10801 University Boulevard, Manassas, Va. 20110-2209on Jul. 30, 1998. The culture access designation is ATCC 74459. Thisdeposit will be maintained in the ATCC for at least 30 years and will bemade available to the public upon the grant of a patent disclosing it.The availability of a deposit does not constitute a license to practicethe subject invention in derogation of patent rights granted bygovernment action.

The protease-producing fungus is a strain Metarhizium anisopliae(MF6527, GB5475) which was isolated from soil collected in secondaryvegetation of a tropical dry forest, Guanacaste National Park,Guanacaste Province, Costa Rica. The fungus is readily identified by itsproduction of compact, dry, dark green sporodochia on agar culturemedia, eg., cornmeal agar or malt extract agar. Microscopically thefungus produces complex, pencillately branched condiophores that giverise to ampulliform, phialidic condiogenesis cells. Conidia are dry,elliptical, smooth and formed in dry chains. The strain conforms in allaspects to modern descriptions of Metarhizium anisopliae (e.g. K. H.Domsch, W. Gams, & T.-H. Anderson. 1980. Compendium of Soil Fungi. Vol.1., Academic Press, London, U.K. pg. 413).

The processes of the present invention provide (+)-S-2 substantiallyfree of its (−)-R-2 enantiomer. The term “substantially free of its(−)-R-2 enantiomer” means that the desired (+)-S-2 enantiomer isobtained in greater than about 75% ee (enantiomeric excess), preferably,greater than about 90% ee, and most preferably, greater than about 98%ee.

The end product Compound A L-tartrate salt, i.e.,(+)-5-Methoxycarbonyl-6-(3,4-difluorophenyl)-4-methoxy-carbonyl-1-{N-[3-(4-(2-pyridyl)piperidin-1-yl)propyl]}-carboxamido-1,2,3,6-tetrahydro-2-oxopyrimidineL-tartrate salt, (1) may be prepared according to Scheme 1 as describedabove.

The present invention further provides a chemical process for making aclass of dihydropyrimidinone compounds of which Compound A is a member.The process for the preparation of a compound of Formula (I):

comprises treating a dihydropyrimidinone of Formula (II):

with a deprotonation agent; then contacting the treateddihydropyrimidinone with 1,1′-carbonyldiimidazole to form anacylimidazolide intermediate; and then contacting the acylimidazolideintermediate with an amine of Formula (III):

H₂N—R  (III)

to form the compound of Formula (I); wherein

R¹, R⁵ and R⁶ are each independently selected from:

1) hydrogen,

2) halogen,

3) C₁₋₁₀ alkyl,

4) C₃₋₈ cycloalkyl,

5) substituted C₁₋₁₀ alkyl, wherein the substituents are independentlyselected from halogen, C₁₋₆ alkoxy, halogen-substituted C₁₋₆ alkoxy,C₃₋₆ cycloalkyl, phenyl, and halogen-substituted phenyl,

6) substituted C₃₋₈ cycloalkyl, wherein the substituents areindependently selected from halogen, C₁₋₆ alkoxy, halogen-substitutedC₁₋₆ alkoxy, C₁₋₆ alkyl, halogen-substituted C₁₋₆ alkyl, phenyl, andhalogen-substituted phenyl,

7) phenyl, and

8) substituted phenyl, wherein the substituents are independentlyselected from halogen, C₁₋₄ alkyl, halogen-substituted C₁₋₄ alkyl,cyano, nitro, and C₁₋₄ alkoxy; or

R¹ is as defined above and R⁵ and R⁶ together form a 3- to 7-memberedsaturated or unsaturated carbocyclic ring or a 4- to 7-memberedsaturated or unsaturated heterocyclic ring, the carbocyclic ring orheterocyclic ring optionally substituted with C₁₋₆ alkyl, wherein theheterocylic ring contains from 1 to 3 heteroatoms independently selectedfrom nitrogen, oxygen, and sulfur,

R² is:

1) hydrogen,

2) hydroxy,

3) C₁₋₁₀ alkyl,

4) halogen-substituted C₁₋₁₀ alkyl,

5) C₁₋₆ alkoxy,

6) halogen-substituted C₁₋₆ alkoxy,

7) C₃₋₆ cycloalkyl, or

8) substituted C₃₋₆ cycloalkyl, wherein the substituents areindependently selected from halogen, hydroxy, C₁₋₆ alkyl,halogen-substituted C₁₋₆ alkyl, and C₁₋₆ alkoxy;

R³ and R⁴ are each independently selected from hydrogen, C₁₋₁₀ alkyl,and the group of Formula (IV):

wherein each Y is independently selected from

1) halogen,

2) cyano,

3) C₁₋₆ alkoxy,

4) nitro,

5) C₁₋₁₀ alkyl, and

6) halogen-substituted C₁₋₁₀ alkyl;

r is an integer of from 0 to 5;

R⁷ is selected from hydrogen and C₁₋₁₀ alkyl; and

R is selected from C₁₋₄₀ hydrocarbyl and substituted C₁₋₄₀ hydrocarbyl.

In the process of the invention:

R¹, R⁵ and R⁶ are preferably each independently selected from hydrogen;halogen; C₁₋₄ alkyl; and substituted C₁₋₄ alkyl, wherein thesubstituents are independently selected from halogen, C₁₋₄ alkoxy, andhalogen-substituted C₁₋₄ alkoxy; and more preferably R⁵ and R⁶ arehydrogen and R¹ is hydrogen, C₁₋₄ alkyl, or C₁₋₄ alkoxy.

R² is preferably hydrogen, C₁₋₄ alkyl, halogen-substituted C₁₋₄ alkyl,or C₁₋₄ alkoxy; is more preferably C₁₋₄ alkyl or C₁₋₄ alkoxy; and ismost preferably C₁₋₄ alkoxy (e.g., methoxy).

R³ and R⁴ are preferably each independently selected from hydrogen, C₁₋₄alkyl, and the group of Formula (IV):

More preferably, R⁴ is hydrogen and R³ is selected from C₁₋₄ alkyl andthe group of Formula (IV). Most preferably, R⁴ is hydrogen and R³ is thegroup of Formula (IV). Y in Formula (IV) is preferably selected fromhalogen, cyano, C₁₋₄ alkoxy, nitro, C₁₋₄ alkyl, and halogen-substitutedC₁₋₄ alkyl; and is more preferably selected from hydrogen, fluorine,cyano, C₁₋₄ alkyl, and trifluoromethyl. r is preferably an integer from0 to 3, and more preferably an integer from 0 to 2.

In another preferred embodiment of the process of the invention, R⁴, R⁵, and R⁶ are each hydrogen.

R⁷ is preferably selected from hydrogen and C₁₋₄ alkyl, and is morepreferably hydrogen.

R is preferably selected from

1) C₁₋₁₆ alkyl,

2) substituted C₁₋₁₆ alkyl wherein the substituents are independentlyselected from halogen, hydroxy, C₃₋₈ cycloalkyl, C₁₋₄ alkoxy, cyano,nitro, NHR^(a), and N(R^(a))₂,

3) C₅₋₇ cycloalkyl,

4) substituted C₅₋₇ cycloalkyl, wherein the substituents areindependently selected from halogen, hydroxy, C₁₋₁₀ alkyl, C₁₋₄ alkoxy,cyano, nitro, NHR^(a), and N(R^(a))₂,

5) phenyl,

6) substituted phenyl, wherein the substituents are independentlyselected from halogen, C₁₋₄ alkyl, halogen-substituted C₁₋₄ alkyl,cyano, nitro, and C₁₋₄ alkoxy, and

7) the group represented by Formula (V):

wherein R⁸ and R⁹ are independently selected from

1) hydrogen,

2) C₁₋₄ alkyl, and

3) C₅₋₇ cycloalkyl;

R¹⁰ is independently selected from

wherein R¹² is selected from

1) phenyl,

2) substituted phenyl, wherein the substituents on the phenyl areindependently selected from halogen, hydroxy, trifluoromethyl, cyano,nitro, C₁₋₄ alkyl, C₁₋₄ alkoxy, NH^(a), and N(R^(a))₂, and

3) unsubstituted or substituted pyridyl, pyridyl N-oxide (N->O),pyrazinyl, thienyl, thiazolyl, furanyl, quinazolinyl, or naphthylwherein the substituents thereon are independently selected fromhalogen, trifluoromethyl, cyano, nitro, C₁₋₄ alkyl, C₁₋₄ alkoxy, phenyl,C₃₋₈ cycloalkyl, NHR^(a), and N(R^(a))₂;

R¹⁴ is selected from

1) hydrogen,

2) cyano,

3) C₁₋₄ alkyl,

4) OR^(b),

5) CO₂R^(b),

6) CON(R^(a))₂,

7) phenyl,

8) substituted phenyl wherein the substituents on the phenyl areindependently selected from halogen, trifluoromethyl, cyano, nitro, C₁₋₄alkyl, C₁₋₄ alkoxy, NHR^(a), and N(R^(a))₂, and

9) unsubstituted or substituted pyridyl, thienyl, furanyl or naphthylwherein the substituents thereon are independently selected fromtrifluoromethyl, phenyl, halogen, C₁₋₄ alkyl, C₁₋₄ alkoxy, and C₃₋₈cycloalkyl;

R¹⁶, R¹⁸, R²⁰ and R²² are each independently selected from hydrogen,C₁₋₁₀ alkyl, C₃₋₈ cycloalkyl, (CH₂)₀₋₄OR^(a), (CH₂)₀₋₄CF₃,(CH₂)₀₋₄CO₂R^(a), (CH₂)₀₋₄CN, (CH₂)₀₋₄NHR^(a), and (CH₂)₀₋₄N(R^(a))₂;

R²⁴ is selected from hydrogen, C₁₋₄ alkyl, and C₅₋₇ cycloalkyl;

R^(a) is C₁₋₄ alkyl;

R^(b) is hydrogen, C₁₋₄ alkyl, C₃₋₈ cycloalkyl, or (CH₂)₁₋₄CF₃;

m, n, o, and p are each independently selected from 0, 1, and 2, withthe proviso that the sum of m+n and the sum of o+p are independentlynever greater than 3; and

q is an integer from 0 to 4

R is more preferably selected from

1) C₃₋₁₂ alkyl,

2) substituted C₃₋₁₂ alkyl wherein the substituents are independentlyselected from halogen, hydroxy, C₁₋₄ alkoxy, cyano, and nitro,

3) C₅₋₇ cycloalkyl,

4) substituted C₅₋₇ cycloalkyl, wherein the substituents areindependently selected from halogen, hydroxy, C₁₋₄ alkyl, C₁₋₄ alkoxy,cyano, and nitro,

5) substituted phenyl, wherein the substituents are independentlyselected from halogen, C₁₋₄ alkyl, halogen-substituted C₁₋₄ alkyl,cyano, nitro, and C₁₋₄ alkoxy; and

6) the group of Formula (V):

R is still more preferably the group of Formula (V). R⁸ and R⁹ arepreferably independently selected from hydrogen and C₁₋₄ alkyl. Morepreferably R⁸ is hydrogen and R⁹ is C₁₋₄ alkyl, and most preferably R⁸and R⁹ are both hydrogen.

R¹⁰ is preferably independently selected from the structure of Formula(VI) and the structure of Formula (VII).

In R¹⁰, R¹² is preferably selected from phenyl; substituted phenyl,wherein the substituents on the phenyl are independently selected fromhalogen, trifluoromethyl, cyano, nitro, C₁₋₄ alkyl, and C₁₋₄ alkoxy; andunsubstituted or substituted pyridyl wherein the substituents on thepyridyl are independently selected from halogen, trifluoromethyl, cyano,nitro, C₁₋₄ alkyl, and C₁₋₄ alkoxy. In another preferred embodiment, R¹²is substituted phenyl wherein the substituents are independentlyselected from fluorine, cyano, C₁₋₄ alkyl, and trifluoromethyl, whereinthe number of substituents on the phenyl is from 1 to 3, preferably from1 to 2.

R¹⁴ is preferably selected from hydrogen; cyano; C₁₋₄ alkyl; OR^(b);phenyl; substituted phenyl wherein the substituents on the phenyl areindependently selected from halogen, trifluoromethyl, cyano, nitro, C₁₋₄alkyl, and C₁₋₄ alkoxy; and unsubstituted or substituted pyridyl whereinthe substituents on the pyridyl are independently selected fromtrifluoromethyl, phenyl, halogen, C₁₋₄ alkyl, and C₁₋₄ alkoxy. Inanother preferred embodiment, R¹⁴ is selected from hydrogen, cyano, C₁₋₄alkyl and OR^(b).

R¹⁶, R¹⁸, R²⁰ and R²² are preferably each independently selected fromhydrogen, C₁₋₄ alkyl, (CH₂)₀₋₄OR^(a), (CH₂)₀₋₄CF₃, (CH₂)₀₋₄CO₂R^(a), and(CH₂)₀₋₄CN; and more preferably selected from hydrogen and C₁₋₄ alkyl.In a preferred embodiment, R¹⁶, R¹⁸, R²⁰ and R²² are all hydrogen.

R²⁴ is preferably selected from hydrogen and C₁₋₄ alkyl, and is morepreferably hydrogen.

R^(a) is preferably methyl or ethyl.

R^(b) is preferably hydrogen or C₁₋₄ alkyl, and is more preferablyhydrogen, methyl, or ethyl.

q is preferably 2 or 3.

In the process of the invention the compound of Formula (I) is preparedby treating a compound of Formula (II) with a deprotonation agent andthen contacting the treated compound of Formula (II) with carbonyldiimidazole, followed by coupling the product thereof with an amine ofFormula (III). The deprotonation agent is an organic or inorganiccompound which is sufficiently basic to accept and bind a proton underthe reaction conditions. In one embodiment, the deprotonation agent isselected from the group consisting of alkali metal carbonates andbicarbonates, alkali metal salts of di -C₁₋₄ alkylamines, alkali metalsalts of C₁₋₆ hydrocarbons (i.e., methane, ethane, and the linear andbranched propanes, butanes, pentanes and hexanes), and alkali metalsalts of bis(tri-C₁₋₄ alkylsilyl)amines. Suitable deprotonation agentsinclude, but are not limited to, lithium diisopropylamide (“LDA”),lithium bis(trimethylsilyl)amide, and butyllithium. LDA is a preferreddeprotonation agent for the process of the invention.

The deprotonation step is typically conducted by treating a thedihydropyrimidinone compound of Formula (II) dissolved or suspended inan inert solvent (e.g., aromatic hydrocarbons such toluene, xylene, andethylbenzene; alkyl ethers such as ethyl ether or THF; aliphatichydrocarbons such as pentane, hexane, or heptane; and mixtures thereof)with the deprotonation agent (e.g., LDA as either a solid or dissolvedor suspended in an aliphatic hydrocarbon, an aromatic hydrocarbon,and/or an ether) for a suitable time and at a suitable temperature forthe deprotonation of the dihydropyrimidinone compound. The order ofaddition is not important here; i.e., the term “treating” here involveseither adding the deprotonation agent to the dihydropyrimidinonecompound or vice versa. The temperature is suitably in the range of fromabout −80 to about 25° C., typically in the range of from about −70 toabout −25° C., and preferably in the range of from about −70 to about−40° C. (e.g., from about −65 to about −55° C.). While the reaction time(i.e., treating time) can vary widely depending upon the choice ofreaction temperature, deprotonation agent, and the particulardihydropyrimidinone reactant employed, it is typically in the range offrom about 5 minutes to about 5 hours, and more typically in the rangeof from about 15 minutes to about 2 hours (e.g., from about 10 to about30 minutes).

Following deprotonation, the deprotonation reaction mixture is contactedwith CDI. The term “contacting” here means that either the CDI is addedto the reaction mixture or the reaction mixture is added to the CDI. Itis more typical to add the CDI to the reaction mixture. The CDI istypically employed as a solid, although a solution or suspension of CDIin an inert solvent such as THF, toluene, or heptane may be usedinstead. The resulting mixture is allowed to react at a temperaturesuitably in the range of from about −80 to about 40° C., and typicallyin the range of from about −70 to about 30° C. (e.g. from about −65 toabout 25° C.) for a time sufficient to form the acyl imidazolide. Thereaction time is suitably in the range of from about 30 minutes to about5 hours, and typically in the range of from about 30 minutes to about 3hours (e.g., from about 45 minutes to about 2 hours). The formation ofthe acylimidazolide can be monitored by HPLC, and the reaction istypically carried out until at least a major portion of the startingdihydropyrimidinone compound has been converted to acyl imidazolide. Thedegree of conversion of dihydropyrimidinone to imidazolide is typicallyat least about 60%, more typically at least about 80%, and preferably atleast about 90%.

Subsequent to the acylimidazolide formation step, theacylimidazolide-containing reaction mixture is contacted with an amineof Formula (III), either by addition of the amine to the reactionmixture or vice versa, to form the compound of Formula (I). It is moretypical to add the amine to the reaction mixture. An amine salt of anorganic (e.g., aliphatic carboxylic acids such as acetic acid) orinorganic acid (e.g., HCl or HBr) may optionally be used in place of theamine itself. The amine is typically dissolved or suspended in an inertsolvent (e.g., aliphatic hydrocarbons such as pentane, hexane, and/orheptane; ethers such as alkyl ethers—ethyl ether—and/or THF, alkylacetates such as isopropyl acetate). The coupling of the amine to thedihydropyrimidinone is typically conducted at a temperature in the rangeof from about −80 to about 40° C., and more typically in the range offrom about −70 to about 30° C. (e.g. from about 15 to about 25° C.). Inone embodiment, the reaction mixture is at a relatively low temperatureduring the addition of the amine (e.g., from about −80 to about −20° C.)and, upon completion of amine addition, is then increased to arelatively high temperature (e.g., from about 0 to about 25° C. ). Thecoupling can be monitored by HPLC analysis and is typically conducteduntil at least a major portion of the acyl imidazolide has beenconverted to the coupled amine product. The degree of conversion ofimidazolide to coupled product is typically at least about 70%, moretypically at least about 85%, and preferably at least about 90%.

After the coupling reaction is completed, the reaction is quenched,typically by the addition of water. The desired compound of Formula (I)can be recovered via conventional separation techniques such asextraction, chromatography, and crystallization.

In the deprotonation step, the deprotonation agent is suitably employedin an amount of from about 0.8 to about 2.0 equivalents, typically in anamount of from about 1.0 to about 1.5 equivalents, and preferably in anamount of from about 1.0 to about 1.3 equivalents, per equivalent of thedihydropyrimidinone compound of Formula (II).

In the acylimidazolide formation step, CDI is employed in an amount ofat least about 1 equivalent, and is suitably in the range of from about1.0 to about 1.5 equivalents of CDI, and is preferably in the range offrom about 1.1 to about 1.3 equivalents (e.g., 1.2 equivalents) of CDI,per equivalent of compound (II). An advantage of the process of theinvention is that only a slight excess of CDI is typically required(e.g., from about 1.1 to about 1.5 equivalents of CDI per equivalent ofcompound (I)) to achieve high rates of conversion (e.g., greater thanabout 85%). When R⁷ is hydrogen (i.e., when both the N-1 and N-3positions on the dihydropyrimidinone ring are unsubstituted), a furtheradvantage of the process of the invention is that the acyl imidazolideforms predominantly or exclusively at the N-3 position of thedihydropyrimidinone ring, so that no deprotection/protection steps arerequired to prevent coupling at the N-1 position.

In the coupling step, the amine is suitably employed in an amount offrom about 1.0 to about 2.5 equivalents, typically in an amount of fromabout 1.1 to about 2.0 equivalents, and preferably in an amount of fromabout 1.1 to about 1.5 equivalents (e.g., from about 1.2 to about 1.5equivalents), per equivalent of the dihydropyrimidinone compound ofFormula (II).

Conversions of at least about 50% (e.g., from about 80% to about 99%) ofthe starting dihydropyrimidinone to coupled amine product can beachieved via the process of the invention.

In a particular illustration of the process of the invention, a processfor preparing a dihydropyrimidinone compound of Formula (XI):

comprises treating a dihydropyrimidinone compound of Formula (XII):

with a deprotonation agent; then contacting the treated compound ofFormula (II) with at least about one equivalent of carbonyldiimidazoleto form an acylimidazolide intermediate; and then contacting with anamine of Formula (XIII):

H₂N—(CH₂)_(q)—R¹⁰  (XIII)

to form compound (XI); wherein

R¹ is selected from halogen, C₁₋₄ alkyl, (CH₂)₀₋₄CF₃, and C₁₋₄ alkoxy;

R² is selected from C₁₋₄ alkyl, (CH₂)₁₋₄CF₃, C₁₋₄ alkoxy, andO(CH₂)₁₋₄CF₃;

each Y is independently selected from halogen (preferably fluorine),cyano, CF₃, nitro, C₁₋₄ alkyl, and C₁₋₄ alkoxy;

R¹⁰ is independently selected from:

 wherein

R¹² is selected from phenyl; substituted phenyl, wherein thesubstituents on the phenyl are independently selected from halogen,trifluoromethyl, cyano, nitro, C₁₋₄ alkyl, and C₁₋₄ alkoxy; andunsubstituted or substituted pyridyl wherein the substituents on thepyridyl are independently selected from halogen, trifluoromethyl, cyano,nitro, C₁₋₄ alkyl, and C₁₋₄ alkoxy;

m and n are independently integers equal to 0 or 1;

q is an integer from 0 to 3; and

r is an integer from 0 to 3.

Illustrative of the compounds preparable by the above process are(4S)-trans-4-(3,4-difluorophenyl)-3-[1-(4-pyridinyl-2-ylcyclohexyl)-(3R)-pyrrolidin-3-ylcarbamoyl]-6-methyl-2-oxo-1,2,3,4-tetrahydro-pyrimidine-5-carboxylicacid methyl ester of structural formula:

and Compound A.

As used herein, the term “C₁₋₄₀ hydrocarbyl” means a radical attached tothe remainder of the molecule by a carbon atom, consisting of carbonatoms and hydrogen atoms and having a total of 1 to 40 carbon atoms.Hydrocarbyl radicals include aliphatic hydrocarbyl groups (e.g., alkyl,alkenyl, or alkynyl), alicyclic hydrocarbyl (e.g., cycloalkyl orcycloalkenyl), aliphatic hydrocarbyl substituted alicyclic hydrocarbyl(e.g., alkyl-substituted cycloalkyl or alkenyl-substituted cycloalkyl),alicyclic hydrocarbyl substituted aliphatic hydrocarbyl (e.g.,cycloalkyl-substituted alkyl or cycloalkyl-substituted alkenyl),aromatic hydrocarbyl (e.g., phenyl or naphthyl), aliphatic- andalicyclic-substituted aromatic, aromatic-substituted aliphatic oralicyclic, and the like.

The term “substituted C₁₋₄₀ hydrocarbyl” means a C₁₋₄₀ hydrocarbyl asdefined above in which (i) one or more of the hydrogen atoms have beenreplaced by one or more non-hydrocarbon substituents such as halogen,hydroxy (—OH), mercapto (—SH), oxo (=O), alkoxy (—O-alkyl) primary amino(—NH₂), N-alkylamino (—NH-alkyl), N,N-dialkylamino (—N(alkyl)₂),carboxamido (—C(=O)NH₂), carboxy (—COOH), alkoxycarbonyl(—C(=O)O-alkyl), alkylcarbonyl (C(=O)-alkyl), formyl (—CHO),nitro(—NO₂), cyano (—CN), and the like, wherein the alkyl is a linear orbranched alkyl; (ii) from one to no more than half (i.e., to no morethan 1 in 2, typically to no more than 1 in 3, more typically to no morethan 1 in 4, and preferably to no more than 1 in 5) of the carbon atoms(whether aliphatic, alicyclic, or aromatic) have been replaced by one ormore heteroatoms such as nitrogen, oxygen, or sulfur; or (iii) acombination of carbon atoms and hydrogen atoms have been replaced inaccordance with (i) and (ii).

The term “C₁₋₁₆ alkyl” refers to a C₁ to C₁₆ linear or branched alkylgroup; i.e., the term includes all of the hexadecyl, pentadecyl,tetradecyl, tridecyl, dodecyl, undecyl, decyl, nonyl, octyl, heptyl,hexyl, and pentyl isomers as well as n-, iso-, sec- and t-butyl, n- orisopropyl, ethyl and methyl. Similarly, “C₁₋₁₀ alkyl” refers to a C₁ toC₁₀ linear or branched alkyl group; i.e., all of the decyl, nonyl,octyl, heptyl, hexyl and pentyl isomers, whether linear or branched, n-,iso-, sec- and t-butyl, n- or isopropyl, ethyl and methyl. “C₁₋₆ alkyl”means a C₁ to C₆ linear or branched alkyl group and refers to all of thehexyl and pentyl isomers, and n-, iso-, sec- and t-butyl, n- orisopropyl, ethyl and methyl. “C₁₋₄ alkyl” means a C₁ to C₄ linear orbranched alkyl group and refers to n-, iso-, sec- and t-butyl, n- orisopropyl, ethyl and methyl. “C₃₋₁₂ alkyl” means a C₃ to C₁₂ linear orbranched alkyl group and refers to the propyl to dodecyl isomersinclusive.

“C₃₋₈ cycloalkyl” means a cyclic ring of an alkane having three to eighttotal carbon atoms (i.e., cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cycloheptyl or cyclooctyl). “C₃₋₆ cycloalkyl” refers to acyclic ring selected from cyclopropyl, cyclobutyl, cyclopentyl, andcyclohexyl. “C₅₋₇ cycloalkyl” refers to a cyclic ring selected fromcyclopentyl, cyclohexyl, and cycloheptyl.

“C₁₋₆ alkoxy” refers to an O-alk group wherein alk represents C₁₋₆ alkylas defined above. Similarly, “C₁₋₄ alkoxy” refers to a O-Alk groupwherein alk represents C₁₋₄ alkyl as defined above.

The term “halogen” refers to fluorine, chlorine, bromine, and iodine.

The term “halogen-substituted C₁₋₁₀ alkyl” means a C₁ to C₁₀ linear orbranched alkyl group as defined above substituted with one or morehalogens. The term “halogen-substituted C₁₋₆ alkyl” means a linear orbranched alkyl group as defined above substituted with one or morehalogens. Similarly, “halogen-substituted C₁₋₄ alkyl” means a C₁ to C₄linear or branched alkyl group as defined above substituted with one ormore halogens. Representative examples of suitable halo-substitutedalkyls include trifluoromethyl, tribromomethyl, 1-fluoroethyl,2-fluoroethyl, 2,2-difluoroethyl, 2,2,2-trifluoroethyl, 2-bromoethyl,3,3,3-trifluoro-n-propyl, 3,3,3-trifluoroisopropyl,1,1,1,3,3,3-hexafluoroisopropyl, and perfluorohexyl

The term “halogen-substituted C₁₋₆ alkoxy” refers to an O-alk groupwherein alk represents C₁₋₆ alkyl as defined above substituted with oneor more halogens. Representative examples include2,2,2-trifluoroethyloxy, 2-fluoroethyloxy, trifluoromethoxy,2-chloroethyloxy, and 3,3,3-trifluoro-n-propyloxy.

The definition of any substituent or variable at a particular locationin a molecule is independent of its definitions elsewhere in thatmolecule. Thus, N(R^(a))2 wherein R^(a) is C₁₋₄ alkyl representsN(CH₃)₂, N(CH₃)(C₂H₅), N(C₂H₅)₂, N(C₂H₅)(C₃H₇), and so forth.

Where multiple substituents are disclosed or claimed, the substitutedcompound can be independently substituted by one or more of thedisclosed or claimed substituent moieties, singly or plurally.

All ranges given for variables defined to be integers are inclusiveranges; e.g., the term “r is an integer of from 0 to 5” means that r canhave any one of the values 0, 1, 2, 3, 4, or 5.

Amines of Formula (III) wherein R is the group represented by Formula(V) wherein R¹⁰ is of Formula (VI) can be prepared in accordance withSchemes 4-7.

Amines of Formula (III) wherein R is the group represented by Formula(V) wherein R¹⁰ is of Formula (VII) can be prepared via the methodsdisclosed in International Publication No. WO 96/14846, published May23, 1996. See, for example, Schemes 1, 6, and 20 therein.

Amines of Formula (III) wherein R is the group represented by Formula(V) wherein R¹⁰ is of Formula (VIII) can be prepared in accordance withSchemes 8-12.

Amines of Formula (III) wherein R is the group represented by Formula(V) wherein R¹⁰ is of Formula (IX) can be prepared in accordance withSchemes 13 and 14.

Amines of Formula (III) wherein R is the group represented by Formula(V) wherein R¹⁰ is of Formula (X) can be prepared in accordance withSchemes 15-20.

Other methods for preparing amines of Formula (III) wherein R is thegroup represented by Formula (V) will be readily apparent to the personof ordinary skill in the art in view of the schemes set forth herein andin WO 96/14846.

The following examples are provided to further define the inventionwithout, however, limiting the invention to the particulars of theseexamples.

EXAMPLE 1 1-(3-aminopropyl)-4-(2-pyridyl)pyridinium bromidehydrobromide, (4)

A solution of 2,4′-dipyridyl (820 g, 5.25 mol) and 3-bromopropylaminehydrobromide (1400 g, 6.39 mol) in DMF (5.0 L) was heated to 95° C. for8 hours. The reaction mixture was cooled to room temperature and methyltert-butyl ether (3.7 L) was added over 3 hours. The slurry was stirredfor 1 hour and filtered. The solid was washed with MTBE/DMF (1:1, 4.2 L)and dried to afford 1-(3-aminopropyl)-4-(2-pyridyl)pyridinium bromidehydrobromide (4) as a tan solid.

EXAMPLE 2 3-[4-(2-pyridyl)-3,4-dehydropiperidin-1-yl]propylamine, (5)

A suspension of 1-(3-aminopropyl)-4-(2-pyridyl)-pyridinium bromidehydrobromide, (4), (1840 g, 4.9 mol) in methanol (18 L) was cooled to 5°C. Sodium borohydride (612 g, 16.2 mol) was added in small portions over2 hours. Methanol was removed by distillation under reduced pressure.Methyltert-butyl ether (10 L) and 20 wt % aqueous NaOH (20 L) wereadded. The mixture was stirred for 20 min and the two layers wereseparated. The aqueous layer was extracted with MTBE (10 L). Thecombined MTBE extract was concentrated under vacuum to afford 5 as athick oil, which was dissolved in MeOH (8 L) and used in the next stepwithout further treatment.

EXAMPLE 3 3-[4-(2-pyridyl)piperidin-1-yl]propylamine, (6)

A solution of 3-[4-(2-pyridyl)-3,4-dehydropiperidin-1-yl]propylamine,(5), (900 g, 4.1 mol) in methanol (9 L) was hydrogenated over Pearlman'scatalyst (90 g) at 40 psi for 2 hours. The slurry was filtered throughCelite® 521, rinsed with methanol (3×300 mL), and the solution wasconcentrated via rotary evaporation to afford3-[4-(2-pyridyl)piperidin-1-yl]propylamine, (6), as thick yellow oil.

EXAMPLE 4 3-[4-(2-pyridyl)piperidin-1-yl]-propylamine L-tartrate salt,(7)

A solution of 3-[4-(2-pyridyl)piperidin-1-yl]propylamine, (6), (637.9 g,3.86 mol) in ethanol (8.5 L) was warmed to 65° C. A solution ofL-tartaric acid (637.9 g, 4.25 mol) in ethanol (2.23 L) was added inportions. Approximately 15% of the tartaric acid solution was added andthen reaction mixture was aged for 1 hour to afford a thin slurry ofcrystalline material. The remaining tartaric acid solution was addeddropwise. Heating was discontinued and the solution was slowly cooled toambient temperature overnight. The solids were filtered, rinsed withethanol (2×1 L) and dried under a stream of nitrogen to afford3-[4-(2-pyridyl)piperidin-1-yl]propylamine L-tartrate salt, (7), as apale yellow solid.

EXAMPLE 5 3-[4-(2-pyridyl)piperidin-1-yl]propylamine, (6)

3-[4-(2-pyridyl)piperidin-1-yl]propylamine L-tartrate salt, (7), (1120g, 3.0 mol) was treated with 5M NaOH (5.7 L, 28.6 mol). The suspensionwas extracted with isopropyl acetate (3×18 L). The combined extractswere concentrated to afford 3-[4-(2-pyridyl)-piperidin-1-yl]propylamine,(6), as a viscous oil.

EXAMPLE 6(±)-5-Methoxycarbonyl-6-(3,4-difluorophenyl)-4-methoxymethyl-1,2,3,6-tetrahydro-2-oxopyrimidine,(2)

A solution of methyl 4-methoxyacetoacetate (702 g, 4.8 mol), urea (433g, 7.2 mol), 3,4-difluorobenzaldehyde (670 g, 4.7 mol), borontrifluoride diethyl etherate(1126 g, 7.9 mol), copper(II) acetate (94 g,0.52 mol), and acetic acid (36 mL) in THF (7.5 L) was heated to refluxfor 8 hours. The reaction mixture was cooled to 20° C. Ethyl acetate (8L) and 10% citric acid aqueous solution (7.5 kg) was added. The twolayers were separated and the aqueous layer was extracted with ethylacetate (4 L). The combined organic layers were washed with 10% aqueoussodium carbonate (2×5 L) and with 5% brine (1×5 L). The organic layerwas concentrated under reduced pressure, with toluene being addedcontinuously and the mixture was concentrated until the level of THF andethyl acetate was <0.5% volume to toluene, to a final volume was about2.5 L. The toluene slurry was warmed to 80° C. to dissolve the solids.The solution was cooled slowly to 60° C. and seeded. The slurry was agedat 60° C. for 1 hour and cooled slowly to 20° C. over 4 hours. Hexane(700 mL) was added over 30 minutes. The slurry was aged for 1 hour andfiltered. The solid was washed with toluene (1.5 L) and dried to afford(+)-2 as a white solid.

EXAMPLE 7(+)-(6S)-5-Methoxycarbonyl-6-(3,4-difluorophenyl)-4-methoxymethyl-1,2,3,6-tetrahydro-2-oxopyrimidine,((+)-2)

A 100-L reaction vessel was charged with 50 mM Tris buffer (Tris HCl(77.4 g) and Tris Base (196.7 g) in deionized water (42.3 L)), 12.0 L ofsubtilisin (PURAFECT® 4000 L, available from Genencor International),acetonitrile (5.7 L), and(±)-5-methoxycarbonyl-6-(3,4-difluorophenyl)-4-methoxymethyl-1,2,3,6-tetrahydro-2-oxopyrimidine,(2), (120 g, 0.38 mol) and the mixture was allowed to react at 37° C.,pH 8.3 for 9 days. The reaction mixture was extracted with toluene (10L). The aqueous layer was separated and washed with toluene (5 L). Thecombined organic extracts were washed with brine (10 L). The organiclayer was concentrated by rotary evaporation, filtered, then adjusted to400 mL volume with toluene. The (+)-2 was crystallized by adding heptane(80 mL), followed by seeding. The mixture was stirred for 1 hr, thenheptane (520 mL) was added over 8 hrs. The crystals were filtered,washed with 3:2 heptane-toluene (150 mL), then dried under high vacuumto yield(+)-(6S)-5-methoxycarbonyl-6-(3,4-difluorophenyl)-4-methoxymethyl-1,2,3,6-tetrahydro-2-oxopyrimidine,((+)-2) as a white solid.

EXAMPLE 8(+)-5-Methoxycarbonyl-6-(3,4-difluorophenyl)-4-methoxycarbonyl-1-{N-[3-(4-(2-pyridyl)piperidin-1-yl)propyl]}carboxamido-1,2,3,6-tetrahydro-2-oxopyrimidine,(3)

A solution of(+)-(6S)-5-methoxycarbonyl-6-(3,4-difluorophenyl)-4-methoxymethyl-1,2,3,6-tetrahydro-2-oxopyrimidine,((+)-2), (100 g, 0.32 mol) in THF (1 L) was cooled to -65° C. A solutionof LDA (2M in heptane/THF/ethylbenzene, 184 mL, 0.36 mol) was added in athin stream. The resulting clear solution was aged for 15 min., thencarbonyl diimidazole (62.3 g, 0.38 mol) was added as a solid in oneportion. The resulting slurry was aged for 15 min at ca. −60° C., thenwarmed to 20° C. and aged for 1 hour. The thin yellow suspension wascooled to −60° C. A solution of3-[4-(2-pyridyl)piperidin-1-yl]propylamine, (6), (100 g, 0.45 mol) inIPAc was added. The reaction mixture was slowly warmed to 20° C. After 1hour at 20° C., the reaction was quenched with H₂O (1.5 L) and IPAc (1.5L). The layers were separated. The organic layer was washed with H₂O(2×1.5 L). The combined aqueous layers were washed with IPAc (1×0.5 L).The combined organic layers were extracted with 2N HCl (1×1 L and 1×0.5L). The combined HCI extracts were neutralized by the cautious additionof solid NaHCO₃ (450 g). IPAc (1 L) and H₂O (1 L) were added to thebicarbonate layer. The layers were separated. The aqueous bicarbonatelayer was washed with IPAc (1×1 L). The combined product containing IPAclayers were washed with H₂O (2×1 L). The organic layer was concentratedto afford(+)-5-methoxycarbonyl-6-(3,4-difluorophenyl)-4-methoxycarbonyl-1-{N-[3-(4-(2-pyridyl)piperidin-1-yl)propyl]}carboxamido-1,2,3,6-tetrahydro-2-oxopyrimidine,(3), as a thick oil.

EXAMPLE 9 Crystallization of(+)-5-Methoxycarbonyl-6-(3,4-difluorophenyl)-4-methoxycarbonyl-1-{N-[3-(4-(2-pyridyl)piperidin-1-yl)propyl]}carboxamido-1,2,3,6-tetrahydro-2-oxopyrimidineL-tartrate salt, (1)

Crude(+)-5-methoxycarbonyl-6-(3,4-difluorophenyl)-4-methoxycarbonyl-1-{N-[3-(4-(2-pyridyl)piperidin-1-yl)propyl]}carboxamido-1,2,3,6-tetrahydro-2-oxopyrimidine,(3), (150 g) was dissolved in 2-propanol (1.27 L) at 50° C.Approximately 50 mL of a solution of L-tartaric acid (40.7 g) in EtOH(175 mL) was added to the solution of 3 at 50° C. The solution was agedfor 1 hour for crystals to develop, then the remaining L-tartaric acidwas added over 0.5 hour. The suspension of 1 was cooled to 20° C. Afterovernight age, the suspension was cooled to 0° C. and filtered. The cakewas rinsed with 2-propanol (2×150 mL) and dried by pulling N₂ throughthe cake to afford(+)-5-methoxycarbonyl-6-(3,4-difluorophenyl)-4-methoxycarbonyl-1-{N-[3-(4-(2-pyridyl)piperidin-1-yl)propyl]}carboxamido-1,2,3,6-tetrahydro-2-oxopyrimidineL-tartrate salt, (1), as a white, free-flowing solid. This crystallineform of (1), designated as Type A, was determined to be an isopropanolsolvate.

¹H NMR (DMSO-d₆): 9.95 (s, 1H), 8.81 (t, J=5.6, 1H), 8.49 (m, 1H), 7.71(td, J=7.8, 1.8, 1H), 7.41 (dt, J=10.5, 8.6, 1H), 7.28 (d, J=7.8, 1H),7.20 (m, 2H), 7.08 (m, 1H), 6.56 (s, 1H), 4.63 (d, J=13.1, 1H), 4.43 (d,J=13.1, 1H), 4.08 (s, 2H), 3.67 (s, 3H), 3.29 (s, 3H), 3.25 (m, 4H),2.79 (m, 1H), 2.71 (t, J=7.3, 2H), 2.52 (m, 2H), 1.89 (m, 4H), 1.78 (m,2H).

¹³C NMR (DMSO-d₆): 173.8, 164.4, 163.4, 152.9, 152.2, 149.2 (dd,J=246.5, 24.7), 149.0 (dd, J=246.5, 24.2), 148.9, 146.8, 138.0 (t,J=4.5), 136.7, 123.0 (dd, J=6.7, 3.5), 121.7, 121.3, 117.9 (d, J=17.2),115.3 (d, J=17.6), 103.1, 71.8, 66.7, 58.2, 54.4, 52.3, 51.8, 51.7,41.9, 38.1, 29.7, 24.9.

Type A is characterized by a differential scanning calorimetry (DSC)curve, at a heating rate of 10° C./min in an open cup under flowingnitrogen, exhibiting a relatively broad endotherm with an extrapolatedonset temperature of about 56° C., a peak temperature of about 90° C.and an associated heat of about 23 J/gm followed by an endotherm with anextrapolated onset temperature of about 108° C., a peak temperature ofabout 115° C. and an associated heat of about 13 J/gm followed by anendotherm with an extrapolated onset temperature of about 145° C., apeak temperature of about 148° C. and an associated heat of about 57J/gm. The two low temperature endotherms are due to the loss ofisopropanol and the high temperature endotherm is due to melting withdecomposition of the remaining unsolvated phase (Type B).

The X-ray powder diffraction pattern of Type A is characterized byd-spacings of 14.91, 8.32, 6.88, 5.41, 4.74, 4.29, 4.04, 3.86, 3.75 and3.59 Å.

A second crystalline form of (1), designated as Type B which isunsolvated material, was prepared either by swishing Type A in ethanolfollowed by filtration and subsequent drying, or by heating Type A to˜115° C. for about 20 minutes.

More specifically, Compound A tartrate salt Type A (2-propanol solvate)(10 g) was suspended in ethanol (50 mL) at 0° C. in a flask fitted witha mechanical stirrer, addition funnel, and thermocouple under a N₂atmosphere. The solution was aged for 2 hours and then filtered. Thecake was rinsed with ethanol (2×5 mL) and dried by pulling N₂ throughthe cake to afford Compound A tartrate salt Type B as a white,free-flowing solid. The ¹H and ¹³C NMR spectra for Type B are identicalto the spectra for Type A shown above.

Type B is characterized by a differential scanning calorimetry (DSC)curve, at a heating rate of 10° C./min in an open cup under flowingnitrogen, exhibiting an endotherm with an extrapolated onset temperatureof about 144° C., a peak temperature of about 148° C. and an associatedheat of about 65 J/gm. The endotherm is due to melting withdecomposition.

The X-ray powder diffraction pattern of Type B is characterized byd-spacings of 13.29, 7.82, 6.63, 6.20, 5.36, 5.01, 4.59, 4.35, 4.05,3.73 and 3.60 Å.

EXAMPLE 10

As a specific embodiment of an oral composition, 100 mg of the compoundof Example 9 (Type B) is formulated with sufficient finely dividedlactose to provide a total amount of 580 to 590 mg to fill a size O hardgel capsule.

EXAMPLE 11 Synthesis of racemic DHP methyl ester, i.e.,(±)-5-Methoxycarbonyl-6-(3,4-difluorophenyl)-4-methoxymethyl-1,2,3,6-tetrahydro-2-oxopyrimidine,(2)

A solution of methyl 4-methoxyacetoacetate (702 g, 4.8 mol), urea (433g, 7.2 mol), 3, 4-difluorobenzaldehyde (670 g, 4.7 mol), borontrifluoride diethyl etherate(1126 g, 7.9 mol), copper(II) acetate (94 g,0.52 mol), and acetic acid (36 mL) in THF (7.5 L) was heated to refluxfor 8 hours. The reaction mixture was cooled to 20° C. Ethyl acetate (8L) and 10% citric acid aqueous solution (7.5 kg) was added. The twolayers were separated and the aqueous layer was extracted with ethylacetate (4 L). The combined organic layers were washed with 10% aqueoussodium carbonate (2×5 L) and with 5% brine (1×5 L). The organic layerwas concentrated under reduced pressure, with toluene being addedcontinuously and the mixture was concentrated until the level of THF andethyl acetate was <0.5% volume to toluene, to a final volume was about2.5 L. The toluene slurry was warmed to 80° C. to dissolve the solids.The solution was cooled slowly to 60° C. and seeded. The slurry was agedat 60° C. for 1 hour and cooled slowly to 20° C. over 4 hours. Hexane(700 mL) was added over 30 minutes. The slurry was aged for 1 hour andfiltered. The solid was washed with toluene (1.5 L) and dried to affordracemic DHP methyl ester, (±)-2, as a white solid

EXAMPLE 12

Enzymatic Screening

An amount of 125 mg of racemic DHP methyl ester ((±)-2) was added to 100ml of Tris buffer (50 mM, pH 7.5) and 500 mg of xanthan gum. The mixturewas blended at high speed in a commercial blender for 2 minutes. Theemulsion was dispensed (10 ml) into 250-ml Erlenmeyer flasks. To eachflask, an enzyme (lipase, esterase, or protease) to be evaluated wasadded. The flasks were incubated at 30° C. Samples (1 ml) were takenafter 24 and 48 hours of incubation and were diluted with 1 ml ofacetonitrile, centrifuged, and filtered. HPLC analyses (method describedbelow) revealed the presence of dihydropyrimidinone acid (8) in theflasks to which 100 mg of Proteinase K or 25 mg of Subtilisin wereadded. SFC analyses (described below) indicated that the acid (8)produced had an enantiomeric excess greater than 95%, and that anenrichment in one of the ester enantiomers had taken place.

Reverse phase HPLC was used to quantitate the ester (2) and acid (8) inthe reaction mixture. The sample was prepared by mixing 1 ml of thereaction mixture with 1 ml acetonitrile. The mixture was filteredthrough a 0.3-μm filter and 10 μl was injected. The column is anInertsil 5 ODS (4.6 mm×25 cm). A gradient elution at 1 ml/min from 25%to 40% acetonitrile in water, each with 0.1% trifluoroacetic acid, isused to detect at 280 nm. The change in chiral purity of the ester (2)with time was monitored using an SFC assay. The samples were prepared byevaporating 0.1 ml reaction mixture under a stream of nitrogen,dissolving the residue in 1 ml methanol, and filtering through a 0.3-μmfilter. The column used is a Chiralcel OD-H (4.6 mm×25 cm). An isocraticelution at 2 ml/min, 35° C., and 290 bar of 6% methanol in CO₂ is usedto detect at 280 nm.

EXAMPLE 13

Bioresolution of Racemic Ester using Proteinase K

A 50 mM Tris buffer was prepared by dissolving 2.46 g Tris HCl and 2.96g Tris Base in 800 ml deionized water. This buffer, along with 4 gxanthan gum and 0.8 g ester (±)-2, was added to a commercial blenderused to emulsify the mixture by blending for 2 min. The resultingemulsion and 8 g Proteinase K (Sigma, 14 U/mg) were added to a 1-Lreaction vessel and allowed to react at 37° C., pH 8.0, and an agitationrate of 300 RPM for 6 days. After 6 days, 89% of the (R)-ester had beenhydrolyzed by the Proteinase K to the acid form, leaving (S)-ester of an80% enantiomeric excess (e.e.). The reaction was diluted with equalvolume of acetonitrile to precipitate the xanthan gum, which was removedby filtration through cotton. The filtrate was evaporated to half volumeby rotary evaporation, and the resulting aqueous liquid was extractedthree times with ethyl acetate. The organic layer was dried overanhydrous MgSO₄ and concentrated by rotary evaporation to yield aresidue, which was purified by silica gel flash chromatography, elutingwith 60-80% ethyl acetate in hexane to yield 0.29 g (72% of theoreticalyield) of (S)-DHP methyl ester ((+)-S -2) (80% e.e.) Pure (R)-DHP acid((−)-R-8) was also isolated. The aqueous layer was acidified withconcentrated HCl, saturated with NaCl, and extracted once with ethylacetate. The organic layer was dried, concentrated, and the residue waspurified by crystallization from methanol. Two crops yielded 0.14 g of(R)-DHP acid ((−)-R-8).

EXAMPLE 14

Bioresolution of 3 g/l Racemic Ester using Subtilisin

A 50 mM Tris buffer was prepared by dissolving 5.2 g Tris HCl and 37.2 gTris Base in 6.8 L deionized water. This buffer, along with 2.0 L of theSubtilisin, PURAFECT® 4000 L, 1.2 L of acetonitrile, and 30 g ester(±)-2 was added to a 14-L reaction vessel and the mixture was allowed toreact at 45° C., pH 8.5, and an agitation rate of 125 RPM for 16 days.An additional 400 ml of Subtilisin was passed through a tangential flowfiltration module (10 kDalton mass exclusion, 2.5 ft² area), exchanginghalf of the volume with Tris buffer of the same makeup as that used inthe reaction. This filtered enzyme and 50 ml acetonitrile were added tothe reaction vessel after the first 13 days of the bioresolution. Theconcentrations of ester (2) and acid (8) and chiral purity of ester inthe reaction were assayed with HPLC and SF-HPLC as described above.After 16 days, 98% of the (R)-ester had been hydrolyzed by theSubtilisin to the acid form, leaving (S)-ester of a 96% e.e. The aqueousmixture was extracted with 3 L+1 L toluene. The combined organic layerswere washed with 2 L brine, filtered through cotton, then rotaryevaporated to ca. 50 ml volume. Ca. 10 ml of hexane was added untilcloudiness persisted, warmed to clear the solution, then allowed to ageovernight to crystallize out the ester. The mother liquor was pouredout, then the crystals were washed twice with 2-3 ml toluene. Thecrystals were dried overnight under high vacuum to afford 9.1 g (60% oftheoretical yield) of (S)-DHP methyl ester, (+)-S -2 (99% e.e.). Theaqueous layer after the toluene extraction was acidified withconcentrated HCl and then saturated with NaCl. The aqueous layer wasextracted once with 4 L ethyl acetate, and the mixture was allowed tosettle. The lower clear aqueous layer was drained, and the upper organiclayer, which was an emulsion with particulates, was swirled with solkafloc and filtered through a glass sintered funnel. The now clear organiclayer of the filtrate was dried over anhydrous MgSO₄ and concentrated byrotary evaporation. The residue was dissolved in 150 ml methanol withheating, seeded with (R)-DHP acid crystals, and allowed to stirovernight at room temperature. The crystals were filtered and washedwith methanol to afford pure acid. After the second crop, a total of 8.6g (60% of theoretical yield, >99% A, >99% e.e.) of (R)-DHP acid,(−)-R-8, was obtained as a fine white solid.

EXAMPLE 15

Bioresolution of 2 g/l Racemic Ester using Subtilisin (10-L Scale)

A 50 mM Tris buffer was prepared by dissolving 12.9 g Tris HCl and 32.8g Tris Base in 7.05 L deionized water. This buffer, along with 2.0 L ofthe Subtilisin, PURAFECT® 4000 L, 0.95 L of acetonitrile, and 20 gester, (±)-2, was added to a 14-L reaction vessel and the mixture wasallowed to react at 37° C., pH 8.3, and an agitation rate of 125 RPM for10 days. The concentrations of ester (2) and acid (8) and chiral purityof ester in the reaction were assayed with HPLC and SF-HPLC as describedabove. After 10 days, >99% of the (R)-ester had been hydrolyzed by theSubtilisin to the acid form, leaving (S)-ester of a 98% e.e. Two 10-Lreactions were combined in a 50-L extractor and were extracted with 4L+2 L toluene. The combined organic layer was washed with 3.5 L brineand then concentrated by rotary evaporation. The residue was dissolvedin toluene, filtered through a glass sintered funnel, and then broughtup to 150 ml total volume in a 1-L 3-neck flask equipped with anoverhead stirrer and an addition funnel. Heptane (55 ml) was added over30 min, and then seed crystals of (S)-DHP methyl ester were added. After1.5 hr stirring to generate the seed bed, 195 ml more heptane were addedover 4 hr. The mixture was allowed to stir overnight and then thecrystals were filtered and washed with 50 ml heptane:toluene (2:1). Thecrystals were dried under a vacuum to yield 18.5 g (46% recovery) of(S)-DHP methyl ester, (+)-S -2 (95 area %, 99.5% e.e.).

EXAMPLE 16

Alternative Purification Conditions

The (S)-DHP methyl ester (+)-S-2 generated in Example 10 could beisolated from the aqueous reaction mixture by extraction with variousorganic solvents such as ethyl acetate, toluene, and dichloromethane.After concentration of the extract, the ester could be purified bysilica gel chromatography or by crystallization. The (S)-DHP methylester, (+)-S-2, could also be isolated from the aqueous mixture bypassing the reaction mixture through a resin column (Supelco SP-207resin), washing the column with water, and eluting the retained esteroff the resin with methanol.

EXAMPLE 17

Bioresolution of 2 g/l Racemic Ester using Subtilisin (1500-L Scale)

A 50 mM Tris buffer was prepared by dissolving 1.3 kg Tris HCl and 5.5kg Tris Base in 1060 L deionized water. This buffer, along with 300 L ofthe Subtilisin, PURAFECT® 4000 L, 140 L of acetonitrile, and 3.2 kgester (±)-2 was added to a 1900-L reaction vessel and the mixture wasallowed to react at 37° C., pH 8.5, and an agitation rate of 50 RPM for10 days. The concentrations of ester (2) and acid (8) and chiral purityof ester (2) in the reaction were assayed with HPLC and SF-HPLC asdescribed above. After 10 days, 98% of the (R)-ester had been hydrolyzedby the Subtilisin to the acid form, leaving (S)-ester of a 97% e.e. Thereaction mixture was extracted with 182 kg+133 kg toluene. The combinedorganic layer was washed with 35 gal brine and then vacuum concentrated,first in a 100-gal tank and then in a 50-L round-bottom flask, to avolume of 3 L. An additional 4 L toluene was charged to the mixture,which was then evaporated down to 3 L. This was repeated a second timeto remove the water azeotropically. The concentrated solution wasfiltered through a sintered funnel into a 50-L round-bottom flask andbrought up to 11 L total volume with fresh toluene. Heptane (95 ml) wasadded to 500 ml of the concentrated toluene solution over 20 min, andthen seed crystals of (S)-DHP methyl ester, (+)-S-2, were added. After 1hr stirring to generate the seed bed, 677 ml more heptane were addedover 6.5 hr. After stirring 1 hr more, the crystals were filtered usinga sintered funnel and washed with 200 ml heptane:toluene (3:2). Thecrystals were dried under a vacuum to yield 58 g ester. Heptane (2 L)was added to the remaining 10.5 L of the concentrated toluene solutionover 20 min, and then the 58 g ester were added as seed crystals. After1 hr stirring to generate the seed bed, 13.8 L more heptane were addedover 8 hr. The mixture was stirred overnight and the crystals werefiltered using a Buchner funnel and washed with 5.7 L heptane:toluene(3:2). The crystals were dried with nitrogen for 8 hr and in an oven for4 days at 30° C. under high vacuum and with a nitrogen sweep. Thisafforded 1.28 kg (40% recovery) of (S)-DHP methyl ester, (+)-S -2 (98%e.e.).

EXAMPLE 18 Synthesis of Compound A from DHP methyl ester: i.e.,(+)-5-methoxycarbonyl-6-(3,4-difluorophenyl)-4-methoxycarbonyl-1-{N-[3-(4-(2-pyridyl)piperidin-1-yl)propyl]}carboxamido-1,2,3,6-tetrahydro-2-oxopyrimidineL-tartrate salt (1)

A solution of (S)-DHP methyl ester, (+)-S -2(100 g, 0.32 mol) in THF (1L) was cooled to −65° C. A solution of LDA (2M inheptane/THF/ethylbenzene, 184 mL, 0.36 mol) was added in a thin stream.The resulting clear solution was aged for 15 min., then carbonyldiimidazole (62.3 g, 0.38 mol) was added as a solid in one portion. Theresulting slurry was aged for 15 min at ca. −60° C., then warmed to 20°C. and aged for 1 hour. The thin yellow suspension was cooled to −60° C.A solution of 3-[4-(2-pyridyl)piperidin-1-yl]propylamine (100 g, 0.45mol) in IPAc was added. The reaction mixture was slowly warmed to 20° C.After 1 hour at 20° C., the reaction was quenched with H₂O (1.5 L) andIPAc (1.5 L). The layers were separated. The organic layer was washedwith H₂O (2×1.5 L). The combined aqueous layers were washed with IPAc(1×0.5 L). The combined organic layers were extracted with 2N HCl (1×1 Land 1×0.5 L). The combined HCl extracts were neutralized by the cautiousaddition of solid NaHCO₃ (450 g). IPAc (1 L) and H₂O (1 L) were added tothe bicarbonate layer. The layers were separated. The aqueousbicarbonate layer was washed with IPAc (1×1 L). The combined productcontaining IPAc layers were washed with H₂O (2×1 L). The organic layerwas concentrated to afford(+)-5-methoxycarbonyl-6-(3,4-difluorophenyl)-4-methoxycarbonyl-1-{N-[3-(4-(2-pyridyl)piperidin-1-yl)propyl]}carboxamido-1,2,3,6-tetrahydro-2-oxopyrimidine(3) as a thick oil. Crude(+)-5-methoxycarbonyl-6-(3,4-difluorophenyl)-4-methoxycarbonyl-1-{N-[3-(4-(2-pyridyl)piperidin-1-yl)propyl]}carboxamido-1,2,3,6-tetrahydro-2-oxopyrimidine,3 (150 g) was dissolved in 2-propanol (1.27 L) at 50° C. Approximately50 mL of a solution of L-tartaric acid (40.7 g) in EtOH (175 mL) wasadded to the solution at 50° C. The solution was aged for 1 hour forcrystals to develop, then the remaining L-tartaric acid was added over0.5 hour. The suspension was cooled to 20° C. After overnight age, thesuspension was cooled to 0° C. and filtered. The cake was rinsed with2-propanol (2×150 mL) and dried by pulling N₂ through the cake to afford(+)-5-methoxycarbonyl-6-(3,4-difluorophenyl)-4-methoxycarbonyl-1-{N-[3-(4-(2-pyridyl)piperidin-1-yl)propyl]}carboxamido-1,2,3,6-tetrahydro-2-oxopyrimidineL-tartrate salt (1) as a white, free-flowing solid. This crystallineform of (1), designated as Type A, was determined to be an isopropanolsolvate.

¹H NMR (DMSO-d₆): 9.95 (s, 1H), 8.81 (t, J=5.6, 1H), 8.49 (m, 1H), 7.71(td, J=7.8, 1.8, 1H), 7.41 (dt, J=10.5, 8.6, 1H), 7.28 (d, J=7.8, 1H),7.20 (m, 2H), 7.08 (m, 1H), 6.56 (s, 1H), 4.63 (d, J=13.1, 1H), 4.43 (d,J=13.1, 1H), 4.08 (s, 2H), 3.67 (s, 3H), 3.29 (s, 3H), 3.25 (m, 4H),2.79 (m, 1H), 2.71 (t, J=7.3, 2H), 2.52 (m, 2H), 1.89 (m, 4H), 1.78 (m,2H).

¹³C NMR (DMSO-d₆): 173.8, 164.4, 163.4, 152.9, 152.2, 149.2 (dd,J=246.5, 24.7), 149.0 (dd, J=246.5, 24.2), 148.9, 146.8, 138.0 (t,J=4.5), 136.7, 123.0 (dd, J=6.7, 3.5), 121.7, 121.3, 117.9 (d, J=17.2),115.3 (d, J=17.6), 103.1, 71.8, 66.7, 58.2, 54.4, 52.3, 51.8, 51.7,41.9, 38.1, 29.7, 24.9.

Type A is characterized by a differential scanning calorimetry (DSC)curve, at a heating rate of 10° C./min in an open cup under flowingnitrogen, exhibiting a relatively broad endotherm with an extrapolatedonset temperature of about 56° C., a peak temperature of about 90° C.and an associated heat of about 23 J/gm followed by an endotherm with anextrapolated onset temperature of about 108° C., a peak temperature ofabout 115° C. and an associated heat of about 13 J/gm followed by anendotherm with an extrapolated onset temperature of about 145° C., apeak temperature of about 148° C. and an associated heat of about 57J/gm. The two low temperature endotherms are due to the loss ofisopropanol and the high temperature endotherm is due to melting withdecomposition of the remaining unsolvated phase (Type B).

The X-ray powder diffraction pattern of Type A is characterized byd-spacings of 14.91, 8.32, 6.88, 5.41, 4.74, 4.29, 4.04, 3.86, 3.75 and3.59 Å.

A second crystalline form of (1), designated as Type B which isunsolvated material, was prepared either by swishing Type A in ethanolfollowed by filtration and subsequent drying, or by heating Type A to˜115° C. for about 20 minutes.

More specifically, Compound A tartrate salt Type A (2-propanol solvate)(10 g) was suspended in ethanol (50 mL) at 0° C. in a flask fitted witha mechanical stirrer, addition funnel, and thermocouple under a N₂atmosphere. The solution was aged for 2 hours and then filtered. Thecake was rinsed with ethanol (2×5 mL) and dried by pulling N₂ throughthe cake to afford Compound A tartrate salt Type B as a white,free-flowing solid. The ¹H and ¹³C NMR spectra for Type B are identicalto the spectra for Type A shown above.

Type B is characterized by a differential scanning calorimetry (DSC)curve, at a heating rate of 10° C./min in an open cup under flowingnitrogen, exhibiting an endotherm with an extrapolated onset temperatureof about 144° C., a peak temperature of about 148° C. and an associatedheat of about 65 J/gm. The endotherm is due to melting withdecomposition.

The X-ray powder diffraction pattern of Type B is characterized byd-spacings of 13.29, 7.82, 6.63, 6.20, 5.36, 5.01, 4.59, 4.35, 4.05,3.73 and 3.60 Å.

EXAMPLE 19

Resolution of Racemic Ester using Metarhizium anisopliae MF 6527

A frozen suspension of the fungus Metarhizium anisopliae MF 6527 (storedin 25% glycerol at −70° C.) was used to inoculate a 250 mL Erlenmeyerflask containing 50 mL of Sabouraud dextrose broth (Difco, DetroitMich.). The flask was incubated at 29° C. with shaking for 72 hours.Four 2-L flasks, containing each 500 mL of Sabouraud dextrose wereinoculated each with 10 mL of the first seed stage and were incubated at29° C. for 48 hours with shaking. The contents of the four 2 L flaskswere pooled and used to inoculate a fermentor containing 180 L ofSabouraud dextrose broth and 0.1% of antifoam P 2000 (Dow Chemical,Midland Mich.). The fermentor was operated at 29° C., with 100 rpmagitation. The culture was aerated by pumping air into the fermentor ata flow of 100 L per minute. The head space of the fermentor wasmaintained at 0.7 bar. The culture was allowed to grow for 20 hours. Avolume of 25 L of culture was transferred from the seed fermentor andused to inoculate a production fermentor containing 600 L of Sabourauddextrose medium supplemented with 2.5 g/l of casamino acids (Difco,Detroit Mich.) and 0.1% of antifoam P 2000. The production fermentor wasoperated at 29° C., with an agitation of 100 rpm. The culture wasaerated by pumping air at a flow of 100 L per minute. The head space ofthe fermentor was maintained at 0.7 bar. The pH of the culture wasmaintained between 7.3 and 7.5 for the duration of the experiment. After170 hours of incubation, the entire contents of the fermentor werepumped through a 0.2 uM membrane and the resulting filtrate was storedat 4° C. overnight. The filtrate was then washed by diafiltrationagainst 2 volumes of 50 mM Tris buffer (pH 8.5), using a 10,000 daltoncut off membrane. The washed fermentation broth was concentrated 26fold, employing the same filtration device and was stored at 4° C. Theconcentrate was further concentrated by 8.3 fold using a 6 square feetregenerated cellulose TFF cartridge (Millipore SK1PC003W4, Millipore,Bedford Mass.) with a 10,000 dalton cut off. Ammonium sulfate (166 g)was slowly added over 20 min to 1 L of the concentrate under stirring,to reach 30% saturation. The mixture was stirred for an additional 20min and was centrifuged at 10,000 rpm for 35 min at 4° C. To theresulting supernatant was added 272 g of ammonium sulfate (over 20 min)under stirring to reach 70% saturation. The mixture was stirred for anadditional 20 min and was centrifuged at 10,000 rpm for 35 min. Theresulting pellet was stored at 4° C. An amount of 3.05 g of pellet wasdissolved into 50 mL of Tris buffer (50 mM, pH 8.5). (±)-2-ester in DMSO(final concentration of 2%) was added to the resuspended pellet at afinal concentration of 1 g/L. The reaction mixture was incubated at 29°C. with stirring. A (S)-DHP methyl ester (+)-S-2 enantiomeric excessgreater than 98% was achieved after 10 days of incubation, as determinedby the SFC assay described in Example 12.

While the foregoing specification teaches the principles of the presentinvention, with examples provided for the purpose of illustration, itwill be understood that the practice of the invention encompasses all ofthe usual variations, adaptations, modifications, deletions or additionsof procedures and protocols described herein, as come within the scopeof the following claims and its equivalents.

What is claimed is:
 1. A process for the preparation of a compound ofFormula (I):

comprises treating a dihydropyrimidinone of Formula (II):

with a deprotonation agent; then contacting the treateddihydropyrimidinone with carbonyldiimidazole to form an acylimidazolideintermediate; and then contacting the acylimidazolide intermediate withan amine of Formula (III):  H₂N—R  (III) to form the compound of Formula(I); wherein R¹, R⁵ and R⁶ are each independently selected from: 1)hydrogen, 2) halogen, 3) C₁₋₁₀ alkyl, 4) C₃₋₈ cycloalkyl, 5) substitutedC₁₋₁₀ alkyl, wherein the substituents are independently selected fromhalogen, C₁₋₆ alkoxy, halogen-substituted C₁₋₆ alkoxy, C₃₋₆ cycloalkyl,phenyl, and halogen-substituted phenyl, 6) substituted C₃₋₈ cycloalkyl,wherein the substituents are independently selected from halogen, C₁₋₆alkoxy, halogen-substituted C₁₋₆ alkoxy, C₁₋₆ alkyl, halogen-substitutedC₁₋₆ alkyl, phenyl, and halogen-substituted phenyl, 7) phenyl, and 8)substituted phenyl, wherein the substituents are independently selectedfrom halogen, C₁₋₄ alkyl, halogen-substituted C₁₋₄ alkyl, cyano, nitro,and C₁₋₄ alkoxy; or R¹ is C₁-C₄ alkoxy and R⁵ and R⁶ are each as definedabove; or R¹ is as defined above and R⁵ and R⁶ together form a 3- to7-membered saturated or unsaturated carbocyclic ring or a 4- to7-membered saturated or unsaturated heterocyclic ring, the carbocyclicring or heterocyclic ring optionally substituted with C₁₋₆ alkyl,wherein the heterocylic ring contains from 1 to 3 heteroatomsindependently selected from nitrogen, oxygen, and sulfur; R² is: 1)hydrogen, 2) hydroxy, 3) C₁₋₁₀ alkyl, 4) halogen-substituted C₁₋₁₀alkyl, 5) C₁₋₆ alkoxy, 6) halogen-substituted C₁₋₆ alkoxy, 7) C₃₋₆cycloalkyl, or 8) substituted C₃₋₆ cycloalkyl, wherein the substituentsare independently selected from halogen, hydroxy, C₁₋₆ alkyl,halogen-substituted C₁₋₆ alkyl, and C₁₋₆ alkoxy; R³ and R⁴ are eachindependently selected from hydrogen, C₁₋₁₀ alkyl, and the group ofFormula (IV):

wherein each Y is independently selected from 1) halogen, 2) cyano, 3)C₁₋₆ alkoxy, 4) nitro, 5) C₁₋₁₀ alkyl, and 6) halogen-substituted C₁₋₁₀alkyl; r is an integer of from 0 to 5; R⁷ is selected from hydrogen andC₁₋₁₀ alkyl; and R is selected from C₁₋₄₀ hydrocarbyl and substitutedC₁₋₄₀ hydrocarbyl.
 2. The process according to claim 1, wherein R isselected from 1) C₁₋₁₆ alkyl, 2) substituted C₁₋₁₆ alkyl wherein thesubstituents are independently selected from halogen, hydroxy, C₃₋₈cycloalkyl, C₁₋₄ alkoxy, cyano, nitro, NHR^(a), and N(R^(a))₂, 3) C₅₋₇cycloalkyl, 4) substituted C₅₋₇ cycloalkyl, wherein the substituents areindependently selected from halogen, hydroxy, C₁₋₁₀ alkyl, C₁₋₄ alkoxy,cyano, nitro, NHR^(a), and N(R^(a))₂, 5) phenyl, 6) substituted phenyl,wherein the substituents are independently selected from halogen, C₁₋₄alkyl, halogen-substituted C₁₋₄ alkyl, cyano, nitro, and C₁₋₄ alkoxy,and 7) the group represented by Formula (V):

wherein R⁸ and R⁹ are independently selected from 1) hydrogen, 2) C₁₋₄alkyl, and 3) C₅₋₇ cycloalkyl; R¹⁰ is independently selected from

wherein R¹² is selected from 1) phenyl 2) substituted phenyl, whereinthe substituents on the phenyl are independently selected from halogen,hydroxy, trifluoromethyl, cyano, nitro, C₁₋₄ alkyl, C₁₋₄ alkoxy,NHR^(a), and N(R^(a))₂, and 3) unsubstituted or substituted pyridyl,pyridyl N-oxide (N->O), pyrazinyl, thienyl, thiazolyl, furanyl,quinazolinyl, or naphthyl wherein the substituents thereon areindependently selected from halogen, trifluoromethyl, cyano, nitro, C₁₋₄alkyl, C₁₋₄ alkoxy, phenyl, C₃₋₈ cycloalkyl, NHR^(a), and N(R^(a))₂; R¹⁴is selected from 1) hydrogen, 2) cyano, 3) C₁₋₄ alkyl, 4) OR^(b), 5)CO₂R^(b), 6) CON(R^(a))₂, 7) phenyl, 8) substituted phenyl wherein thesubstituents on the phenyl are independently selected from halogen,trifluoromethyl, cyano, nitro, C₁₋₄ alkyl, C₁₋₄ alkoxy, NHR^(a), andN(R^(a))₂, and 9) unsubstituted or substituted pyridyl, thienyl, furanylor naphthyl wherein the substituents thereon are independently selectedfrom trifluoromethyl, phenyl, halogen, C₁₋₄ alkyl, C₁₋₄ alkoxy, and C₃₋₈cycloalkyl; R¹⁶, R¹⁸, R²⁰ and R²² are each independently selected fromhydrogen, C₁₋₁₀ alkyl, C₃₋₈ cycloalkyl, (CH₂)₀₋₄OR^(a), (CH₂)₀₋₄CF₃,(CH₂)₀₋₄CO₂R^(a), (CH₂)₀₋₄CN, (CH₂)₀₋₄NHR^(a), and (CH₂)₀₋₄N(R^(a))₂;R²⁴ is selected from hydrogen, C₁₋₄ alkyl, and C₅₋₇ cycloalkyl; R^(a) isC₁₋₄ alkyl; R^(b)is hydrogen, C₁₋₄ alkyl, C₃₋₈ cycloalkyl, or(CH₂)₁₋₄CF₃; m, n, o, and p are each independently selected from 0, 1,and 2, with the proviso that the sum of m+n and the sum of o+p areindependently never greater than 3; and q is an integer from 0 to
 4. 3.The process according to claim 2, wherein R^(l), R⁵ and R⁶ are eachindependently selected from hydrogen, halogen, C₁₋₄ alkyl, andsubstituted C₁₋₄ alkyl, wherein the substituents are independentlyselected from halogen, C₁₋₄ alkoxy, and halogen-substituted C₁₋₄ alkoxy;R² is hydrogen, C₁₋₄ alkyl, halogen-substituted C₁₋₄ alkyl, or C₁₋₄alkoxy; R³ and R⁴ are each independently selected from hydrogen, C₁₋₄alkyl, and the group of Formula (IV):

R⁷ is selected from hydrogen and C₁₋₄ alkyl; R is selected from 1) C₃₋₁₂alkyl, 2) substituted C₃₋₁₂ alkyl wherein the substituents areindependently selected from halogen, hydroxy, C₁₋₄ alkoxy, cyano, andnitro, 3) C₅₋₇ cycloalkyl, 4) substituted C₅₋₇ cycloalkyl, wherein thesubstituents are independently selected from halogen, hydroxy, C₁₋₄alkyl, C₁₋₄ alkoxy, cyano, and nitro, 5) substituted phenyl, wherein thesubstituents are independently selected from halogen, C₁₋₄ alkyl,halogen-substituted C₁₋₄ alkyl, cyano, nitro, and C₁₋₄ alkoxy, and 6)the group of Formula (V):

wherein R¹⁰ is independently selected from the structure of Formula (VI)and the structure of Formula (VII); R¹² is selected from phenyl;substituted phenyl, wherein the substituents on the phenyl areindependently selected from halogen, trifluoromethyl, cyano, nitro, C₁₋₄alkyl, and C₁₋₄ alkoxy; and unsubstituted or substituted pyridyl whereinthe substituents on the pyridyl are independently selected from halogen,trifluoromethyl, cyano, nitro, C₁₋₄ alkyl, and C₁₋₄ alkoxy; R¹⁴ isselected from hydrogen; cyano; C₁₋₄ alkyl; OR^(b); phenyl; substitutedphenyl wherein the substituents on the phenyl are independently selectedfrom halogen, trifluoromethyl, cyano, nitro, C₁₋₄ alkyl, and C₁₋₄alkoxy; and unsubstituted or substituted pyridyl wherein thesubstituents on the pyridyl are independently selected fromtrifluoromethyl, phenyl, halogen, C₁₋₄ alkyl, and C₁₋₄ alkoxy; R¹⁶, R¹⁸,R²⁰ and R²² are each independently selected from hydrogen, C₁₋₄ alkyl,(CH₂)₀₋₄OR^(a), (CH₂)₀₋₄CF₃(CH₂)₀₋₄CO₂R^(a), and (CH₂)₀₋₄CN; and R²⁴ isselected from hydrogen and C₁₋₄ alkyl.
 4. The process according to claim2, wherein R¹ is hydrogen, C₁₋₄ alkyl, or C₁₋₄ alkoxy; R⁵ and R⁶ areeach hydrogen; R² is C₁₋₄ alkyl or C₁₋₄ alkoxy; R³ is selected from C₁₋₄alkyl and the group of Formula (IV) R⁴ is hydrogen; R⁷ is selected fromhydrogen and C₁₋₄ alkyl; R is the group of Formula (V):

wherein either R⁸ is hydrogen and R⁹ is C₁₋₄ alkyl, or R⁸ and R⁹ areboth hydrogen; R¹² is selected from phenyl; substituted phenyl, whereinthe substituents on the phenyl are independently selected from halogen,trifluoromethyl, cyano, nitro, C₁₋₄ alkyl, and C₁₋₄ alkoxy; andunsubstituted or substituted pyridyl wherein the substituents on thepyridyl are independently selected from halogen, trifluoromethyl, cyano,nitro, C₁₋₄ alkyl, and C₁₋₄ alkoxy; R¹⁴ is selected from hydrogen;cyano; C₁₋₄ alkyl; OR^(b); phenyl; substituted phenyl wherein thesubstituents on the phenyl are independently selected from halogen,trifluoromethyl, cyano, nitro, C₁₋₄ alkyl, and C₁₋₄ alkoxy; andunsubstituted or substituted pyridyl wherein the substituents on thepyridyl are independently selected from trifluoromethyl, phenyl,halogen, C₁₋₄ alkyl, and C₁₋₄ alkoxy; and r is an integer from 0 to 3.5. The process according to claim 2, wherein R¹ is selected fromhalogen, C₁₋₄ alkyl, (CH₂)₀₋₄CF₃, and C₁₋₄ alkoxy; R² is selected fromC₁₋₄ alkyl, (CH₂)₁₋₄CF₃, C₁₋₄ alkoxy, and O(CH₂)₁₋₄CF₃; R³ is a group ofFormula (IV):

wherein each Y is independently selected from halogen, cyano, CF₃,nitro, C₁₋₄ alkyl, and C₁₋₄ alkoxy; R⁴, R⁵, R⁶, and R⁷ are eachhydrogen; R is (CH₂)_(q)R¹⁰ wherein R¹⁰ is independently selected from:

 wherein R¹² is selected from phenyl; substituted phenyl, wherein thesubstituents on the phenyl are independently selected from halogen,trifluoromethyl, cyano, nitro, C₁₋₄ alkyl, and C₁₋₄ alkoxy; andunsubstituted or substituted pyridyl wherein the subsitituents on thepyridyl are independently selected from halogen, trifluoromethyl, cyano,nitro, C₁₋₄ alkyl, and C₁₋₄ alkoxy; m and n are independently integersequal to 0 or 1; q is an integer from 0 to 3; and r is an integer from 0to
 3. 6. The process according to claim 5 for the preparation of(4S)-trans-4-(3,4-difluorophenyl)-3-[1-(4-pyridinyl-2-ylcyclohexyl)-(3R)-pyrrolidin-3-ylcarbamoyl]-6-methyl-2-oxo-1,2,3,4-tetrahydro-pyrimidine-5-carboxylicacid methyl ester of structural forrnula:

and Compound A, of structural formula:


7. The process according to claim 1, wherein the deprotonation agent isselected from the group consisting of alkali metal carbonates andbicarbonates, alkali metal salts of di-C₁₋₄ alkylamines, alkali metalsalts of C₁₋₆ hydrocarbons, and alkali metal salts of bis (tri-C₁₋₄alkylsilyl)amines.